a(n) = 10^n - 2^n + 1^n.

Terms

a(0) =1a(1) =9a(2) =97a(3) =993a(4) =9985a(5) =99969a(6) =999937a(7) =9999873a(8) =99999745a(9) =999999489a(10) =9999998977a(11) =99999997953a(12) =999999995905