a(n) = 2^n - 10.

Terms

a(0) =-9a(1) =-8a(2) =-6a(3) =-2a(4) =6a(5) =22a(6) =54a(7) =118a(8) =246a(9) =502a(10) =1014a(11) =2038a(12) =4086a(13) =8182a(14) =16374a(15) =32758a(16) =65526a(17) =131062a(18) =262134a(19) =524278a(20) =1048566a(21) =2097142a(22) =4194294a(23) =8388598a(24) =16777206a(25) =33554422a(26) =67108854a(27) =134217718a(28) =268435446a(29) =536870902