#Help_

54 messages · Page 1 of 1 (latest)

stray sableBOT
subtle bane
#

@steady fern

#

@steady fern a partition is basically a sum of integers that sum up of a total n.

#

@steady fern

steady fern
#

I've never seen this before but it looks interesting.

looks like we need a construction methodology for generating symmetric partitions

techinically, this would be recursion not induction

subtle bane
#

the thing is we are asked to not do a generating function;

#

@steady fern We can utilize this so called Ferrers diagrams to consturct symmetric partitions

steady fern
#

ok

#

I'd start out examining simple symmetric partitions and looking for patterns

#

I think I got it

subtle bane
#

ok, I am still figuring out what k can be to make it a symmetric, cause like for n=9, I have k=5 a symmetric, can it be greater or less thatn 5 I do not know

steady fern
#

for n=9, k<=5

e.g. 9 = 6 + 1 + 1 + 1 //only 4 elements, fail

#

lets look at this example where n = 11 and k = 4

#

what does the pink represent?

subtle bane
#

Is the larget k

#

and green are the n-k

steady fern
#

n-2k+1

subtle bane
#

this is the formula of largest k ?

#

cause it gives 4 for , n=9 , when palguing in n-2k+1

#

oh, green is n-2k+1

#

For induction : We can calculate for n=11, and then extend to n+1 , but k should be fixed

steady fern
#

recursion not induction

subtle bane
#

ok

steady fern
#

lets look at n = 17, k = 5

subtle bane
#

I think the first one is 16 not 17 tho

steady fern
subtle bane
#

both are symmetric

steady fern
#

maybe this will help:

subtle bane
#

we see the diagonal stays fixed but we can move the last 2 blue into green

subtle bane
#

Is this the goal?

steady fern
#

ignoring pink, green and blue are the instances that solve P(8,4) and P(8,3) respectively

#

P(8,2) and P(8,1) have no solutions

subtle bane
#

But are not we suppsoed to fix k , and vary n

#

Also, are u saying that a symmetric Ferrers diagram can be built from a previous diagram if we remove the 1st row and column and so on?

#

Can we split k into cases when k is even and when k is odd?

steady fern
steady fern
subtle bane
# steady fern yes

by doing this we vary k, we need where k is fixed i think ,and only n varies

steady fern
#

think about it. I fear I've already been a little too heavy handed with my hints

#

but feel free to ask questions

subtle bane
#

and for k =2: we have : 2 1; 2 2

#

This is the formual we need to deduce

steady fern
#

aren't we trying to find P(n,k)?

subtle bane
#

we are looking for formual to count symmetric P(n,k), such that k is fixed but n is varying

steady fern
#

I'm defining P(n,k) as the number of symmetric partitions of n into k bins

#

if P(n,k) is all partitions, rename my function S(n,k)

#

if you want every symmetric partition where k is fixed but n can vary, then sum(S(n,k) for all n)

#

or bound it, it doesn't need to be an infinite sum since most of them will be 0