OFFSET
0,3
LINKS
Winston de Greef, Table of n, a(n) for n = 0..385
FORMULA
a(n) = Sum_{k=0..floor(n/4)} (n-3*k)^(n-2*k) * binomial(n-3*k,k).
PROG
(PARI) my(N=20, x='x+O('x^N)); Vec(sum(k=0, N, (k*x*(1+k*x^3))^k))
(PARI) a(n) = sum(k=0, n\4, (n-3*k)^(n-2*k)*binomial(n-3*k, k));
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Feb 18 2023
STATUS
approved