a(n) = 2^n + 6.

Terms

a(0) =7a(1) =8a(2) =10a(3) =14a(4) =22a(5) =38a(6) =70a(7) =134a(8) =262a(9) =518a(10) =1030a(11) =2054a(12) =4102a(13) =8198a(14) =16390a(15) =32774a(16) =65542a(17) =131078a(18) =262150a(19) =524294a(20) =1048582a(21) =2097158a(22) =4194310a(23) =8388614a(24) =16777222a(25) =33554438a(26) =67108870a(27) =134217734a(28) =268435462a(29) =536870918