A377452 E.g.f. satisfies A(x) = 1/(1 - A(x) * (exp(x) - 1))^2.

1, 2, 16, 224, 4612, 126392, 4340836, 179534504, 8693925172, 482731239032, 30243460133956, 2110849596096584, 162438922745208532, 13665129603889106072, 1247684652874279407076, 122885960933254703151464, 12987106624622962667192692, 1466014441678589235669027512

Offset: 0

Author

Seiichi Manyama, Oct 28 2024

Keywords

• nonn

Crossrefs

Cf. A052895, A377453, A377454.

Cf. A367161.

Programs

PARI

a(n) = 2*sum(k=0, n, (3*k+1)!/(2*k+2)!*stirling(n, k, 2));

Formula

E.g.f.: B(x)^2, where B(x) is the e.g.f. of A367161.

a(n) = 2 * Sum_{k=0..n} (3*k+1)!/(2*k+2)! * Stirling2(n,k).