factorial(n) - A049614(n).

Terms

a(0) =0a(1) =0a(2) =1a(3) =5a(4) =20a(5) =116a(6) =696a(7) =5016a(8) =40128a(9) =361152a(10) =3611520a(11) =39899520a(12) =478794240a(13) =6226813440a(14) =87175388160