a(n) = 8^n + n.

Terms

a(0) =1a(1) =9a(2) =66a(3) =515a(4) =4100a(5) =32773a(6) =262150a(7) =2097159a(8) =16777224a(9) =134217737a(10) =1073741834a(11) =8589934603a(12) =68719476748a(13) =549755813901