OFFSET
0,2
FORMULA
E.g.f.: Sum_{n>=0} a(n) * x^(3*n+1) / (3*n+1)! = x/(1 - x^3)^(1/3).
a(n) ~ sqrt(2*Pi) * 3^(3*n + 3/2) * n^(3*n + 5/6) / (Gamma(1/3) * exp(3*n)). - Vaclav Kotesovec, Oct 10 2022
PROG
(PARI) {a(n) = (3*n+1)!/(3^n*n!) * prod(k=1, n, 3*k-2)}
for(n=0, 20, print1(a(n), ", "))
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Oct 10 2022
STATUS
approved