a(n) = (n+1)*2^n*(2*n)!.A065141a(n) = (n+1)*2^n*(2*n)!.Terms a(0) =1a(1) =8a(2) =288a(3) =23040a(4) =3225600a(5) =696729600a(6) =214592716800External referencesoeis: A065141