a(n) = 9^n - 9*n.

Terms

a(0) =1a(1) =0a(2) =63a(3) =702a(4) =6525a(5) =59004a(6) =531387a(7) =4782906a(8) =43046649a(9) =387420408a(10) =3486784311a(11) =31381059510a(12) =282429536373