a(n) = 8^n - n^12.

Terms

a(0) =1a(1) =7a(2) =-4032a(3) =-530929a(4) =-16773120a(5) =-244107857a(6) =-2176520192a(7) =-13839190049a(8) =-68702699520a(9) =-282295318753a(10) =-998926258176a(16) =0