OFFSET
0,2
FORMULA
E.g.f. satisfies A(x) = 1/(1 - x * A(x) * exp(x*A(x)))^3.
E.g.f.: B(x)^3, where B(x) is the e.g.f. of A365177.
a(n) = 3 * n! * Sum_{k=0..n} k^(n-k) * binomial(3*n+k+3,k)/( (3*n+k+3)*(n-k)! ).
PROG
(PARI) my(N=20, x='x+O('x^N)); Vec(serlaplace(serreverse(x*(1-x*exp(x))^3)/x))
(PARI) a(n) = 3*n!*sum(k=0, n, k^(n-k)*binomial(3*n+k+3, k)/((3*n+k+3)*(n-k)!));
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Oct 31 2024
STATUS
approved