A360991 Expansion of e.g.f. exp(exp(x) - 1 + x^2/2).

1, 1, 3, 8, 30, 117, 533, 2599, 13919, 79620, 487810, 3167265, 21744187, 157020697, 1189321019, 9417789650, 77774264012, 668233623419, 5961395449795, 55117233908411, 527263186773227, 5210880621612366, 53130216638022540, 558176360466846439

Offset

0,3

Links

Table of n, a(n) for n=0..23.

Formula

a(0) = a(1) = 1; a(n) = (n-1) * a(n-2) + Sum_{k=1..n} binomial(n-1,k-1) * a(n-k).

Prog

(PARI) my(N=30, x='x+O('x^N)); Vec(serlaplace(exp(exp(x)-1+x^2/2)))

Crossrefs

Cf. A097514, A355337, A361489.

Sequence in context: A148888 A151440 A213860 * A361135 A348662 A162560

Adjacent sequences: A360988 A360989 A360990 * A360992 A360993 A360994

Keyword

nonn,easy

Author

Seiichi Manyama, Mar 14 2023

Status

approved