A047677 Row 2 of square array defined in A047675: 2*n!*(n+1)!.

2, 4, 24, 288, 5760, 172800, 7257600, 406425600, 29262643200, 2633637888000, 289700167680000, 38240422133760000, 5965505852866560000, 1085722065221713920000, 228001633696559923200000, 54720392087174381568000000, 14883946647711431786496000000

Offset: 0

Author

N. J. A. Sloane

Keywords

• nonn

Comments

a(n) = A152877(2n+1, 2n-2) for n > 0. - Alois P. Heinz, Nov 10 2013

Crossrefs

Cf. A047675, A010790, A152877.

Programs

Maple

a:= proc(n) a(n):= `if`(n=0, 2, n*(n+1) * a(n-1)) end:
seq(a(n), n=0..20);  # Alois P. Heinz, Nov 11 2013

Mathematica

2*Times@@@Partition[Range[0,20]!,2,1] (* Harvey P. Dale, Sep 25 2017 *)