a(n) = (8*10^n - 71)/9 for n > 0.

Terms

a(0) =1a(1) =81a(2) =881a(3) =8881a(4) =88881a(5) =888881a(6) =8888881a(7) =88888881a(8) =888888881a(9) =8888888881a(10) =88888888881a(11) =888888888881