A368771 a(n) = (n!)^3 * Sum_{k=0..n} k^2/(k!)^3.

0, 1, 12, 333, 21328, 2666025, 575861436, 197520472597, 101130481969728, 73724121355931793, 73724121355931793100, 98126805524745216616221, 169563119946759734312830032, 372530174523031136285287580473, 1022222798891197437966829120818108

Offset: 0

Author

Seiichi Manyama, Jan 05 2024

Keywords

• nonn

Crossrefs

Cf. A368769, A368770, A368772.

Cf. A368775.

Programs

PARI

a(n) = n!^3*sum(k=0, n, k^2/k!^3);

Formula

a(0) = 0; a(n) = n^3 * a(n-1) + n^2.

a(n) = n^2 * A368775(n-1) for n > 0.