a(n) = (11^(n+1) - 1)/10.

Terms

a(0) =1a(1) =12a(2) =133a(3) =1464a(4) =16105a(5) =177156a(6) =1948717a(7) =21435888a(8) =235794769a(9) =2593742460a(10) =28531167061a(11) =313842837672