A368775 a(n) = (n+1) * (n!)^3 * Sum_{k=0..n} 1/((k+1) * (k!)^3).

1, 3, 37, 1333, 106641, 15996151, 4031030053, 1580163780777, 910174337727553, 737241213559317931, 810965334915249724101, 1177521666296942599394653, 2204320559307876546066790417, 5215422443322435907994026126623

Offset: 0

Author

Seiichi Manyama, Jan 05 2024

Keywords

• nonn

Crossrefs

Cf. A217284, A368776.

Cf. A228229, A368771.

Programs

PARI

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

Formula

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