A377692 E.g.f. satisfies A(x) = (1 - log(1 - x) * A(x))^2.

1, 2, 12, 118, 1634, 29408, 654040, 17362056, 536410200, 18922946928, 750902659200, 33118793900784, 1607673329621712, 85192554602094912, 4894219487974911552, 303021216528999244416, 20116223556200658052992, 1425479651299747192856832, 107400336067263661850548224

Offset

0,2

Links

Table of n, a(n) for n=0..18.

Formula

E.g.f.: 4/(1 + sqrt(1 + 4*log(1-x)))^2.

E.g.f.: B(x)^2, where B(x) is the e.g.f. of A052803.

a(n) = 2 * Sum_{k=0..n} (2*k+1)!/(k+2)! * |Stirling1(n,k)|.

Prog

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

Crossrefs

Cf. A007840, A377693.

Cf. A052803, A377445.

Sequence in context: A279201 A121425 A132692 * A009546 A009748 A212414

Adjacent sequences: A377689 A377690 A377691 * A377693 A377694 A377695

Keyword

nonn

Author

Seiichi Manyama, Nov 04 2024

Status

approved