11^n+2^n-1.

Terms

a(0) =1a(1) =12a(2) =124a(3) =1338a(4) =14656a(5) =161082a(6) =1771624a(7) =19487298a(8) =214359136a(9) =2357948202a(10) =25937425624a(11) =285311672658