a(n) = n! * (n+1)! * (n+2)! * (n+3).A084259a(n) = n! * (n+1)! * (n+2)! * (n+3).Terms a(0) =6a(1) =48a(2) =1440a(3) =103680a(4) =14515200a(5) =3483648000External referencesoeis: A084259