a(n)! begins with 2^n.

Terms

a(0) =1a(1) =2a(2) =8a(3) =14a(4) =89a(5) =164a(6) =18a(7) =266a(8) =304a(9) =292a(10) =2522a(11) =557a(12) =26438a(13) =27045a(14) =57134a(15) =21936