A371143 E.g.f. satisfies A(x) = 1 + x*A(x)^3 * (exp(x) - 1).

1, 0, 2, 3, 76, 365, 9906, 94507, 2832824, 43209945, 1438766830, 30971280791, 1146868043124, 32166137748901, 1322928667341386, 45791799761422275, 2085517396191903856, 85748423669245738673, 4306944218393176448742, 204597526239295278145327

Offset

0,3

Links

Table of n, a(n) for n=0..19.

Formula

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

Prog

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

Crossrefs

Cf. A052848, A371142.

Cf. A371141.

Sequence in context: A276197 A042233 A176290 * A370988 A371269 A377690

Adjacent sequences: A371140 A371141 A371142 * A371144 A371145 A371146

Keyword

nonn

Author

Seiichi Manyama, Mar 12 2024

Status

approved