A134374 a(n) = ((2n+1)!)^2.

1, 36, 14400, 25401600, 131681894400, 1593350922240000, 38775788043632640000, 1710012252724199424000000, 126513546505547170185216000000, 14797530453474819213543604224000000

Offset: 0

Author

Artur Jasinski, Oct 22 2007

Keywords

• nonn
• easy

Crossrefs

Cf. A000142, A001044, A000442, A036740, A010050, A009445, A134366, A134367, A134368, A134369, A134371, A134372, A134373, A134375, A334378.

Programs

Maple

A134374:=n->((2*n+1)!)^2; seq(A134374(n), n=0..10); # Wesley Ivan Hurt, May 02 2014

Mathematica

Table[((2n+1)!)^(2), {n, 0, 10}]

PARI

a(n) = ((2*n+1)!)^2; \\ Michel Marcus, Nov 16 2020

Formula

a(n) = A009445(n)^2 = A001044(2n+1). - Wesley Ivan Hurt, May 02 2014

From Amiram Eldar, Nov 16 2020: (Start)

Sum_{n>=0} 1/a(n) = A334378.

Sum_{n>=0} (-1)^n/a(n) = Im(BesselJ(0, 2*exp(3*Pi*i/4))). (End)