#I forget how we found this problem

1324 messages · Page 2 of 2 (latest)

cunning stump
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I think im done

cunning stump
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But im rage quiting

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I tried taking the list of tables and just like remove duplicates but its now even bigger number

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If im coding ever again it will be in a purely functional programming lang

tough kettle
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noo

cunning stump
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My code found 563 unique combinations for f(5 , 5)

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I dont know how

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I removed all duplicates and i dont think my code can give wrong combintions

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I would have to code now a program that takes a combination , validates it ,and ....

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@tough kettle is there some part of your code that takes a combination and gives like True if it really is and false if it isnt

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Or like do you have that

tough kettle
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yeah

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except its bad

cunning stump
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It can be slow it would be really helpfull to debug my program with that

tough kettle
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it doesn't work

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well it doesn't work in c

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i think it works in python

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you generate some bitmasks and do some bitwise ops

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f.py is somewhere up there

cunning stump
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Whats the input?

subtle lake
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i'm working on my algorithm rn

tough kettle
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ok the thing inside the if inside the nested loops validates stuff

cunning stump
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No but im asking what kind of structure does it take

tough kettle
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g is an int which represents a binary grid

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so like

cunning stump
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My table is basically a list of white cells

tough kettle
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ah

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ok

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uh

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so like

cunning stump
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[(X_1 , Y_1) , (X_2 , Y_2) ... ]

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Where those are white cells

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Saves on memory ig

tough kettle
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lets say g is 0b10010110100101110, m is 4, n is 4
so the grid here is 1001 \n 0110 \n 1001 \n 0110

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this is how my program achieves its speed lol

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the 1s are white cells, the 0s are black cells

cunning stump
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Hmm i think for my case i will just like write a loop that loops through whole table

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And just does a check if any whites can be placed

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It should be all false

tough kettle
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i'll replace it with my code when you send it

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to make it faster

cunning stump
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Ok i found the extra ones

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They are just wrong

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The new problem now is that without those extra ones my program undercounts

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For every larger n im just fixing my code

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Thats how many flaws it has

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First it did f(3 , 3) wrong and i fixed it. Then it did f(4 , 4) and i fixed it now f(5 , 5) is wrong

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Im kind of asking myself is my algorithm even consistent or will i have to fix it for every laeger n

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Oh i see the problem

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I thought that this cell was always safe in my algorithm

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So i didnt bother to check if white cell can be placed there

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I think thats the last flaw in my algorithm

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Ok i should prob rewrite my whole algorithm because its getting ugly

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This problem has given me nothing other than pain and suffering

subtle lake
cunning stump
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If my algorithm isnt polynomial time then this wasnt worth it

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I mean on paper it souns fast. As everything you do will be to get a combination so there is no extra checking stuff

subtle lake
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so it's supposed to be O(however many grids there are)?

cunning stump
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Well it would seem to me that it would be something like that but idk in practice how would you calculate big O of that algo

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I mean there are more operations done

subtle lake
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that doesn't seem very fast on paper to me

cunning stump
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I mean it is how a human would manually calculate this

subtle lake
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i wouldn't

cunning stump
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How would you?

subtle lake
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the same way my algorithm does (which i've just been mysteriously mentioning a lot because i'm not sure if people want it spoiled yet)

cunning stump
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Ok well imma try and finish this

tough kettle
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ok

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lets see

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woah the sync is crazy

cunning stump
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My program is undercounting....

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Again

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How do i see a difference between 2 lists?

subtle lake
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difference in what way?

cunning stump
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Like [1 , 2 ,3 , 4] and [1 , 2 ,3] it would be [4]

subtle lake
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python?

cunning stump
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Yes

subtle lake
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you could make them sets and set difference

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might lose some information like the order though

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and like if you want [1 , 2 , 3 , 3, 4] and [1 , 2 ,3] to return [3, 4] then that wouldn't work ofc

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you could use Counter if you wanted that ig

cunning stump
cunning stump
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My algorithm has so many edge cased

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I did it

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It works

subtle lake
cunning stump
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Damn this solved 7x7 in seconds and im on my phone

subtle lake
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coding on your phone?

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damn

cunning stump
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Like i code on a computer only when its multiple file project

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Like svelte or something like that

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Idk how

subtle lake
cunning stump
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That.... is slow right?

subtle lake
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yes

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my algorithm

cunning stump
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Is it also written in python?

subtle lake
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yea

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i just ran both of them in separate jupyter notebook cells in the same file

cunning stump
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Well my time wasnt that well spent then ig

subtle lake
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wasn't spent too terribly

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got something out of it

cunning stump
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Is your algorithm pure python or like uses alot of functions from C?

subtle lake
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but yea at least one operation for each valid grid is not going to be pretty limiting

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just python

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just simple python objects, no numpy or anything

cunning stump
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Thats cool

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I mean how does your algorithm scale

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What about f(9 , 9) or something like thaz

subtle lake
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f(n+1, n+1) takes about 3x as long as f(n,n). but f(2n,n) only takes (about) twice as long as f(n,n)

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so as long as min(m,n) isn't too big, one of the numbers can go really high

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like f(5,10^6) for example i've computed

cunning stump
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So like f(n , n) has big O of 3^n?

subtle lake
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yea

cunning stump
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I dont really know what big O of my algo should be

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Imma ask chat gpt

subtle lake
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i believe it is exponential

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in mn

cunning stump
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But im not checking every combination

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Im only checking every combination that makes sense

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Aka every combination that will give me a solution

subtle lake
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predictions on f(8,8)?

cunning stump
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Like few minutes ig

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Or even hours

subtle lake
cunning stump
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Well yes

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I would say my algorithm is polynomial in that

subtle lake
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polynomial in what?

cunning stump
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And due to that being exponential then it probably also is

cunning stump
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Like f(n , n)^6

subtle lake
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not constant?

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yea you're cooked

subtle lake
# subtle lake

f(n+1,n+1) is at least 2*f(n,n) so that's already at least exponential for your algorithm

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but it's much worse than that message makes it sound because the multiplier is much bigger than 2 (and grows)

cunning stump
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Or maybe more like f(n , n) *n^6

subtle lake
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f(8,8) still hasn't finished and i need to leave my computer

cunning stump
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Whats max you computed?

subtle lake
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with my algorithm?

cunning stump
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Yes

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f(n , n) not f(n , m)

subtle lake
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i don't think i've bothered going higher than 15

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i could tell you f(19,19) but it would have to be later today joyspin

cunning stump
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So you got to 15. In how much time?

subtle lake
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like 4 minutes probably?

subtle lake
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and because it's past the oeis page

cunning stump
subtle lake
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i gtg away from my computer for a while

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i'll post what f(19,19) is sometime later

tough kettle
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@cunning stump hows your algorithm going

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oh wow

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nice

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now its time to turn it into c

cunning stump
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Im guessing previous calculated f(n , n) would be given as an input?

subtle lake
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i don’t go through them all

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and no i don’t use f(n-1,n-1) to assist in computing f(n,n)

cunning stump
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So basically magic

subtle lake
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pretty much

cunning stump
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Are you like calculating some other sequence and then getting this sequence in terms of that?

subtle lake
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it shouldn’t be that unbelievable though. to count the subsets of a size 100 set that are size 50 you don’t need to go through all 2^100 sets and check their size

cunning stump
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So is your algorithm like lego pieces and then you just connect them?

subtle lake
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kinda

subtle lake
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this is like 20 questions 😂

cunning stump
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I mean it looks like you arent actually calculting every solution. But rather something else and then number of solutions is in terms of that thing.

subtle lake
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there are sequences involved but that’s not really the main idea. they just happen to be made along the way

cunning stump
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This sequence can be written in terms of other sequences

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Which may be easier to compute

subtle lake
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what exactly are you referring to?

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well in any case i didn’t do anything related to anything on that page

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but that is interesting hmmge

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Inverse of 1334th cyclotomic polynomial.

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wtf

twilit seal
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name drop for why

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ummm no

rapid ravine
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u literally called yourself "no one"

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in the sense that u said if someone looks you in the eyes they'll have "nothing" staring back at them

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that implies self deprecation in the sense that you're nothing

cunning stump
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You compute $$F\left( \sum_{k = 1}^n (4k ) + 1\right)$$

dapper wedgeBOT
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Pluton

cunning stump
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Of this

subtle lake
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i didn’t do that but now i’m sad i won’t be at my computer for a while because i want to see how high i can go with that

cunning stump
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What even is that seq

rapid ravine
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i love it when i see people that are smarter when it comes to maths then me

cunning stump
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"Array read by antidiagonals: T(m,n) is the number of maximal independent sets in the m X n king graph."

rapid ravine
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so many weird english words to discover

subtle lake
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but in a sequence

cunning stump
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Oh

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Oh so its useless

subtle lake
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i may be able to abuse it

cunning stump
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How?

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Its basically just says hey f(n , n) is on f(n , m) when n = m

subtle lake
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ah

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i misread it

subtle lake
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then yea that’s useless lol

twilit seal
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thats not self deprecating

rapid ravine
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elaborate

twilit seal
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i know my worth .

rapid ravine
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your worth is nothing then

twilit seal
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Take that back

rapid ravine
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or do u mean it in a more uh

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maam it was a question

twilit seal
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im joking haha

rapid ravine
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not affirming anything

twilit seal
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im kinda busy atm

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ill get back yo u

rapid ravine
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either way maybe u meant it in a more "I won't give you attention" way

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like u wont look back at the person, i dunno

rapid ravine
cunning stump
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It seems like the lcm one could be useful

subtle lake
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just in convoluted ways

cunning stump
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a(n)=lcm(A015343(n), A332347(A001844(n)))

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Like if A001844(n) is less than sum of 4n + 1

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Then it should be easier to compute maybe

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And if A015343(n) is easier to compute

cunning stump
rapid ravine
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unrelated but i found this funni

cunning stump
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And maybe possibly f(n , m) that is easier to compute than f(n , n)

subtle lake
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my hopes are not very high

cunning stump
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You have to compute A332347(2n(n + 1) + 1)

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Now just because its a big number doesnt mean its hard to compute

subtle lake
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what pairs (m,n) do those correspond to?

cunning stump
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It could be f(2 , m) as far as we know

cunning stump
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Wont be that hard to get i think

lunar shoal
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I sorted forum by recent and found this huge thread

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did you find the algorithm yet?

subtle lake
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i wouldn’t say that

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but also welcome waves

lunar shoal
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problem seems fun, i'll think about it

subtle lake
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yea i’ve had a lot of fun with it

cunning stump
subtle lake
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lol rip

cunning stump
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2n(n + 1) + 1 is the sum of 4n + 1

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What is lcm doing?

subtle lake
cunning stump
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I guess its saying that the random thing divides that number

subtle lake
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the fact that they all used the array read by anti-diagonals and that already has the sequence we want embedded inside it was sus

cunning stump
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Yeah

subtle lake
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easy to just grab the (n,n) parts out of it

subtle lake
cunning stump
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But its 0 sometimes

subtle lake
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not before 18 or whatever

cunning stump
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And lcm( 0 , x) ....

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Oh yeah

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Does it mean a_(19) is undefined blobwg

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Makes no sense ik

subtle lake
cunning stump
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A finite grid with non finite ammount of combinations

subtle lake
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it means we can scrap that because it’s just coincidence

cunning stump
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It looks cool

subtle lake
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true

subtle lake
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f(19,19) = 8909115018130190380110405132161117908

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now i sleep

teal tide
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now you sleep

twilit seal
rapid ravine
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so like

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head in the clouds?

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like if someone stares at you you're not actually looking back cause you're distracted?

twilit seal
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no not like that

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idk how to say

rapid ravine
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smh

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u gotta explain yourself woman

subtle lake
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f(20,20) = 75332748233894465141809677114505805331037

vivid pulsar
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What

subtle lake
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just posting some numbers that go past the oeis page for f(n,n)

twilit seal
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how long do these take to compute

subtle lake
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left it running overnight

twilit seal
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owie

eternal thistle
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Goated

tough kettle
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just run it as a direct process to make it much faster

subtle lake
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what does that mean

tough kettle
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lol

tough kettle
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actually run it with dandidapython

twilit seal
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jupyter uses cpython

tough kettle
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yeah but its slow

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you can see by the cpu times

tough kettle
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x

azure compass
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@tough kettle hi!!!!
is it ok if i participate here????

tough kettle
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yeah

azure compass
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thanks!!!!

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also what are the 14 solutions for 3x3? i only got 12

tough kettle
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i call them solutions

azure compass
tough kettle
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keepalive

vivid pulsar
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keepalive?

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also is anyone here doing usamts

violet pond
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im writing up my solutions rn 😄

tough kettle
vivid pulsar
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i did like half my prob 5 at 3-4 am today so not it looks so jumpleb😭

violet pond
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lol ye

vivid pulsar
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im doing prob 4 last omg its so hard to explain

violet pond
vivid pulsar
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ok