a(n) = n!*(n+1)!.A010790a(n) = n!*(n+1)!.Terms a(0) =1a(1) =2a(2) =12a(3) =144a(4) =2880a(5) =86400a(6) =3628800a(7) =203212800a(8) =14631321600External referencesoeis: A010790