a(n) = 8^n - n^10.

Terms

a(0) =1a(1) =7a(2) =-960a(3) =-58537a(4) =-1044480a(5) =-9732857a(6) =-60204032a(7) =-280378097a(8) =-1056964608a(9) =-3352566673a(10) =-8926258176a(11) =-17347490009a(12) =6802112512a(13) =411897322039