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A258296
Number of partitions of 2*n^2 into parts that are at most n.
5
1, 1, 5, 37, 351, 3765, 43752, 536375, 6842599, 89984614, 1212199424, 16651935901, 232477235048, 3290090540717, 47106320777132, 681247106742555, 9938641464083052, 146113228303254020, 2162784490438698636, 32209221982817148364, 482304350308369699381
OFFSET
0,3
LINKS
FORMULA
a(n) ~ c * d^n / n^2, where d = 16.57962120993269533568313969522872808998..., c = 0.07942450354657307077058855728600800998... .
MAPLE
T:=proc(n, k) option remember; `if`(n=0 or k=1, 1, T(n, k-1) + `if`(n<k, 0, T(n-k, k))) end proc: seq(T(2*n^2, n), n=0..20);
MATHEMATICA
(* A program to compute the constant d = 16.5796212... *) With[{j=2}, r^(2*j+1)/(r-1) /.FindRoot[-PolyLog[2, 1-r] == (j+1/2)*Log[r]^2, {r, E}, WorkingPrecision->100]] (* Vaclav Kotesovec, Jun 10 2015 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Vaclav Kotesovec, May 25 2015
STATUS
approved