a(n) = 10^n - 8^n.

Terms

a(0) =0a(1) =2a(2) =36a(3) =488a(4) =5904a(5) =67232a(6) =737856a(7) =7902848a(8) =83222784a(9) =865782272a(10) =8926258176a(11) =91410065408a(12) =931280523264