A377742 E.g.f. satisfies A(x) = exp(x) / (1 - x * A(x))^2.

1, 3, 23, 331, 7133, 205901, 7470475, 326932299, 16768124217, 986753701657, 65548017270791, 4852285640543639, 396133183892522389, 35359325061987638661, 3426053898460864501251, 358128187005971803014211, 40172982580368589391407217, 4813677071886578522596221233

Offset

0,2

Links

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

Formula

a(n) = n! * Sum_{k=0..n} (k+1)^(n-k-1) * binomial(3*k+1,k)/(n-k)!.

Prog

(PARI) a(n) = n!*sum(k=0, n, (k+1)^(n-k-1)*binomial(3*k+1, k)/(n-k)!);

Crossrefs

Cf. A194471, A377743, A377744.

Cf. A001339, A377745.

Cf. A377503.

Sequence in context: A129458 A118184 A027486 * A092664 A363577 A260509

Adjacent sequences: A377739 A377740 A377741 * A377743 A377744 A377745

Keyword

nonn

Author

Seiichi Manyama, Nov 05 2024

Status

approved