a(n) = 11^n - 2^n + 1.

Terms

a(0) =1a(1) =10a(2) =118a(3) =1324a(4) =14626a(5) =161020a(6) =1771498a(7) =19487044a(8) =214358626a(9) =2357947180a(10) =25937423578a(11) =285311668564