a(n) = 7*11^n+1.

Terms

a(0) =8a(1) =78a(2) =848a(3) =9318a(4) =102488a(5) =1127358a(6) =12400928a(7) =136410198a(8) =1500512168a(9) =16505633838a(10) =181561972208