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

Terms

a(0) =1a(1) =0a(2) =-510a(3) =-19677a(4) =-262120a(5) =-1953005a(6) =-10076976a(7) =-40348567a(8) =-134177408a(9) =-387057609a(10) =-996371200a(11) =-2318030891a(12) =-4680778752a(13) =-4377478573a(14) =66517244416