a(n) = 9^n - 8^n + 1.

Terms

a(0) =1a(1) =2a(2) =18a(3) =218a(4) =2466a(5) =26282a(6) =269298a(7) =2685818a(8) =26269506a(9) =253202762a(10) =2413042578a(11) =22791125018a(12) =213710059746