a(n) = 9^n - 8^n.

Terms

a(0) =0a(1) =1a(2) =17a(3) =217a(4) =2465a(5) =26281a(6) =269297a(7) =2685817a(8) =26269505a(9) =253202761a(10) =2413042577a(11) =22791125017a(12) =213710059745