A371272 E.g.f. satisfies A(x) = 1 + x*A(x)^3 * (exp(x*A(x)^3) - 1).

1, 0, 2, 3, 148, 905, 40506, 542437, 25080392, 562677201, 28058678110, 908452740701, 49777760550684, 2120072013408505, 128583516119137730, 6778703037793746165, 455574282215526201616, 28520235381763443992993, 2118889776612629769160518

Offset

0,3

Links

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

Formula

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

Prog

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

Crossrefs

Cf. A371231.

Sequence in context: A254787 A042073 A124236 * A115231 A378839 A371231

Adjacent sequences: A371269 A371270 A371271 * A371273 A371274 A371275

Keyword

nonn

Author

Seiichi Manyama, Mar 16 2024

Status

approved