a(n) = 8*10^n + 1.

Terms

a(0) =9a(1) =81a(2) =801a(3) =8001a(4) =80001a(5) =800001a(6) =8000001a(7) =80000001a(8) =800000001a(9) =8000000001a(10) =80000000001a(11) =800000000001