a(n)=10^n-2*n.

Terms

a(0) =1a(1) =8a(2) =96a(3) =994a(4) =9992a(5) =99990a(6) =999988a(7) =9999986a(8) =99999984a(9) =999999982a(10) =9999999980a(11) =99999999978a(12) =999999999976