a(n) = (1/11) * (5*12^n + 6).

Terms

a(0) =1a(1) =6a(2) =66a(3) =786a(4) =9426a(5) =113106a(6) =1357266a(7) =16287186a(8) =195446226a(9) =2345354706a(10) =28144256466a(11) =337731077586