A129933 a(n) = (n*(n+1)/2+1)!/n!.

1, 2, 12, 840, 1663200, 174356582400, 1561112121913344000, 1754317855900734514790400000, 341362923889542287855059017400320000000, 15163751542692044063740921044974247390216192000000000, 195932150519417838363658963697014150610807423633478962380800000000000

Offset: 0

Author

N. J. A. Sloane, Jun 06 2007

Keywords

• nonn

Crossrefs

Cf. A000124, A107868, A129893.

Programs

Mathematica

Table[(n (n+1)/2+1)!/n!,{n,0,20}] (* Harvey P. Dale, Aug 04 2022 *)