n^k - n! where n^k > n! >= n^(k-1).

Terms

a(0) =2a(1) =3a(2) =40a(3) =5a(4) =576a(5) =11767a(6) =221824a(7) =168561a(8) =6371200a(9) =174442081a(10) =4680778752a(11) =4377478573a(12) =202076363776