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

%I #16 Mar 07 2020 01:35:54

%S 2,4,24,288,5760,172800,7257600,406425600,29262643200,2633637888000,

%T 289700167680000,38240422133760000,5965505852866560000,

%U 1085722065221713920000,228001633696559923200000,54720392087174381568000000,14883946647711431786496000000

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

%C a(n) = A152877(2n+1, 2n-2) for n > 0. - _Alois P. Heinz_, Nov 10 2013

%p a:= proc(n) a(n):= `if`(n=0, 2, n*(n+1) * a(n-1)) end:

%p seq(a(n), n=0..20); # _Alois P. Heinz_, Nov 11 2013

%t 2*Times@@@Partition[Range[0,20]!,2,1] (* _Harvey P. Dale_, Sep 25 2017 *)

%Y Cf. A047675, A010790, A152877.

%K nonn

%O 0,1

%A _N. J. A. Sloane_