a(n) = (2*n+1)!*(2*n-2)!/(2*((n-1)!)*(n!)^2), n=1,2,... .
A113677
a(n) = (2*n+1)!*(2*n-2)!/(2*((n-1)!)*(n!)^2), n=1,2,... .
Terms
- a(0) =3a(1) =30a(2) =840a(3) =37800a(4) =2328480a(5) =181621440a(6) =17124307200
External references
- oeis: A113677
A113677
a(n) = (2*n+1)!*(2*n-2)!/(2*((n-1)!)*(n!)^2), n=1,2,... .