A082292 a(n) = (2n+1) * (2n)! / sqrt(4*(n+1)*Product_{k=1..2n+1} lcm(k, 2n+2-k)).

1, 1, 2, 12, 4, 8, 72, 160, 16, 3456, 32, 1792, 129600, 1024, 128, 1492992, 256, 2048000, 18289152, 180224, 1024, 573308928, 1280000, 1703936, 241864704, 719323136, 8192, 64497254400000, 16384, 33554432, 234125033472, 142606336

Offset: 2

Author

Ralf Stephan, Apr 08 2003

Keywords

• nonn

Crossrefs

Cf. A082022.

Programs

Mathematica

Table[((2n+1)(2n)!)/Sqrt[4(n+1)Product[LCM[k,2n+2-k],{k,2n+1}]],{n,2,40}] (* Harvey P. Dale, Aug 01 2020 *)

PARI

for(i=2, 20, n=i*2+1; p=1; for(k=1, n, p=p*lcm(k, n+1-k)); print1((2*i+1)*(2*i)!/sqrtint(4*(i+1)*p)", "))