a(n) = 11^n - 2^n.

Terms

a(0) =0a(1) =9a(2) =117a(3) =1323a(4) =14625a(5) =161019a(6) =1771497a(7) =19487043a(8) =214358625a(9) =2357947179a(10) =25937423577a(11) =285311668563