OFFSET
0,3
FORMULA
a(0) = 1; a(n) = (n-1)! * Sum_{k=1..n} (3*k)! * a(n-k) / (6^k * (n-k)!).
PROG
(PARI) my(N=20, x='x+O('x^N)); Vec(serlaplace(exp(sum(k=1, N, (3*k)!*(x/6)^k/k))))
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Feb 08 2024
STATUS
approved