OFFSET
0,3
FORMULA
G.f.: Sum_{k>=0} k^(k^2) * x^k/(1 + k^k * x).
a(n) ~ n^(n^2). - Vaclav Kotesovec, Dec 10 2021
PROG
(PARI) a(n) = sum(k=0, n, (-1)^(n-k)*k^(k*n));
(PARI) my(N=10, x='x+O('x^N)); Vec(sum(k=0, N, k^k^2*x^k/(1+k^k*x)))
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Dec 04 2021
STATUS
approved