a(n) = 9^n - n^10.

Terms

a(0) =1a(1) =8a(2) =-943a(3) =-58320a(4) =-1042015a(5) =-9706576a(6) =-59934735a(7) =-277692280a(8) =-1030695103a(9) =-3099363912a(10) =-6513215599a(11) =5443635008a(12) =220512172257