[seqfan] Re: checking a sequence before submission
Benoît Jubin
benoit.jubin at gmail.com
Tue Dec 14 00:03:52 CET 2010
On Mon, Dec 13, 2010 at 7:37 AM, David Newman <davidsnewman at gmail.com> wrote:
> Hi Sequence Fans,
>
> I'd like someone to check a sequence for me before I submit it,
> having had the unpleasant experience of submitting an incorrect
> sequence in the past.
>
> For a given positive integer, n, let S_n be the set of partitions
> of n into distinct parts where the number of parts is maximal for that
> n. For example, for n=6, the set S_6 consists of just one such
> partition S_6={1,2,3}. Similarly, for n=7, S_7={1,2,4}, But for n=8,
> S_8 will contain two partitions S_8= { {1,2,5}, {1,3,4} }.
It might be worth mentioning in the new entry that |S_n| = A144328(n)
(if the offset of the latter is changed to 0 -- should it be
changed?), and also to mention this fact in the entry for A144328.
Benoit
>
> Now form the sum 1+ x/(1-x) + x^2/(1-x^2) + x^3/ ( ( 1-x)
> (1-x^2)) + x^4/ ( ( 1-x) (1-x^3) ) + x^5/ ( (1-x) (1-x^4) ) + x^5 (
> ( 1-x^2) (1-x^3)) + x^6/ ( ( 1-x) (1-x^2) (1-x^3)) + ...
>
> whose general term is x^n divided by the product
> (1-x^(p_1))...(1-x^(p_i)) where the p's come from the partitions in
> S_n.
>
> The sequence is the sequence of coefficients of this sum.
>
> The numbers that I've gotten are
> 1,1,2,2,4,6,7,10,14,20,24,32,40,54,69,86,106,135,165,206,256,311,378,460,555,670,808,970,1156,1380,1638,1938,2296,2706,3188,3752,4390,5136
>
> If anyone is willing to do the calculations I can make the Mathematica
> program which I used available to them .
>
>
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