A368853 a(n) = n! * (n+1)! * Sum_{k=0..n} (-1)^k/(k! * (k+1)!).

1, 1, 7, 83, 1661, 49829, 2092819, 117197863, 8438246137, 759442152329, 83538636756191, 11027100051817211, 1720227608083484917, 313081424671194254893, 65747099180950793527531, 15779303803428190446607439, 4291970634532467801477223409

Offset

0,3

Links

Table of n, a(n) for n=0..16.

Formula

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

a(n) ~ BesselJ(1,2) * n! * (n+1)!. - Vaclav Kotesovec, Jan 08 2024

Prog

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

Crossrefs

Cf. A000166, A368854.

Cf. A228229.

Sequence in context: A240170 A231259 A187649 * A316377 A053128 A027819

Adjacent sequences: A368850 A368851 A368852 * A368854 A368855 A368856

Keyword

nonn,easy

Author

Seiichi Manyama, Jan 07 2024

Status

approved