a(n) = n! - n^6.

Terms

a(0) =1a(1) =0a(2) =-62a(3) =-723a(4) =-4072a(5) =-15505a(6) =-45936a(7) =-112609a(8) =-221824a(9) =-168561a(10) =2628800a(11) =38145239a(12) =476015616a(13) =6222193991a(14) =87170761664