A379934 E.g.f. A(x) satisfies A(x) = 1/( exp(-x*A(x)) - x )^2.

1, 4, 38, 626, 15008, 476122, 18864124, 898099526, 49988162672, 3187006372466, 229091274174404, 18335328399262030, 1617287276785929928, 155893591123924724618, 16304903025947743812476, 1839154613521698544945238, 222562344165125395485931232, 28763041177430039602579211746

Offset: 0

Author

Seiichi Manyama, Jan 06 2025

Keywords

• nonn

Crossrefs

Cf. A379933, A379936.

Cf. A379864, A379884.

Programs

PARI

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

Formula

E.g.f.: B(x)^2, where B(x) is the e.g.f. of A379884.

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