a(n) = 2^n + 8.

Terms

a(0) =9a(1) =10a(2) =12a(3) =16a(4) =24a(5) =40a(6) =72a(7) =136a(8) =264a(9) =520a(10) =1032a(11) =2056a(12) =4104a(13) =8200a(14) =16392a(15) =32776a(16) =65544a(17) =131080a(18) =262152a(19) =524296a(20) =1048584a(21) =2097160a(22) =4194312a(23) =8388616a(24) =16777224a(25) =33554440a(26) =67108872a(27) =134217736a(28) =268435464a(29) =536870920