OFFSET
0,3
LINKS
Winston de Greef, Table of n, a(n) for n = 0..152
FORMULA
a(n) = Sum_{k=1..n} k^(3*k) * binomial(n-1,k-1) for n > 0.
PROG
(PARI) my(N=20, x='x+O('x^N)); Vec(sum(k=0, N, (k^3*x/(1-x))^k))
(PARI) a(n) = if(n==0, 1, sum(k=1, n, k^(3*k)*binomial(n-1, k-1)));
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Jul 04 2022
STATUS
approved