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

0,2

Links

Table of n, a(n) for n=0..17.

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).

Prog

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

Crossrefs

Cf. A052895, A377453, A377454.

Cf. A367161.

Sequence in context: A188844 A187657 A047657 * A233141 A377445 A223631

Adjacent sequences: A377449 A377450 A377451 * A377453 A377454 A377455

Keyword

nonn

Author

Seiichi Manyama, Oct 28 2024

Status

approved