A363355 E.g.f. satisfies A(x) = exp(x * A(x) * (1 + x * A(x)^2)).

1, 1, 5, 46, 641, 11996, 282907, 8060242, 269429729, 10341367480, 448317429011, 21667926214694, 1155321200076529, 67370686916807236, 4265392644606677963, 291391173322695366106, 21365209437807863776193, 1673543873372595900318704

Offset: 0

Author

Seiichi Manyama, Aug 17 2023

Keywords

• nonn

Crossrefs

Cf. A088695, A362771, A363356.

Cf. A365012.

Programs

PARI

a(n) = n!*sum(k=0, n, (2*n-k+1)^(k-1)*binomial(k, n-k)/k!);

Formula

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