%I #14 Dec 06 2021 03:10:37
%S 1,1,2,10,93,1307,28002,842196,33388393,1717595949,111931584098,
%T 8979468552886,872315432217509,101425775048588759,
%U 13924209725224120770,2229705716369149960592,412760812611799202662609,87644186710319273062637625,21180850892383599137766296770
%N Expansion of Sum_{k>=0} x^k/(1 - k^3 * x).
%H Seiichi Manyama, <a href="/A349880/b349880.txt">Table of n, a(n) for n = 0..246</a>
%F a(n) = Sum_{k=0..n} k^(3*(n-k)).
%F a(n) ~ sqrt(2*Pi/3) * (n/LambertW(exp(1)*n))^(1/2 + 3*n - 3*n/LambertW(exp(1)*n)) / sqrt(1 + LambertW(exp(1)*n)). - _Vaclav Kotesovec_, Dec 04 2021
%o (PARI) a(n, s=0, t=3) = sum(k=0, n, k^(t*(n-k)+s));
%o (PARI) my(N=20, x='x+O('x^N)); Vec(sum(k=0, N, x^k/(1-k^3*x)))
%Y Cf. A026898, A234568, A349881.
%Y Cf. A349857.
%K nonn
%O 0,3
%A _Seiichi Manyama_, Dec 03 2021