A377358 E.g.f. satisfies A(x) = ( 1 - log(1 - x*A(x))/A(x) )^2.

1, 2, 4, 22, 194, 2268, 34272, 624804, 13432120, 332078160, 9286572624, 289821031344, 9985648515504, 376489542984384, 15418392593403360, 681562973789926560, 32345053760113660800, 1640243700728870131200, 88516191520113318169344, 5064936155664187593030912

Offset: 0

Author

Seiichi Manyama, Oct 26 2024

Keywords

• nonn

Crossrefs

Cf. A377325, A377359.

Cf. A377349.

Programs

PARI

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

Formula

E.g.f.: B(x)^2, where B(x) is the e.g.f. of A377349.

a(n) = 2 * Sum_{k=0..floor((2*n+2)/3)} (2*n-2*k+1)!/(2*n-3*k+2)! * |Stirling1(n,k)|.