a(n) = Sum_{0<j<n} (n!-j!).

Terms

a(0) =1a(1) =9a(2) =63a(3) =447a(4) =3447a(5) =29367a(6) =276327a(7) =2856807a(8) =32250087a(9) =395130087a(10) =5225062887a(11) =74201293287