a(n) = 2^n - n^3.

Terms

a(0) =1a(1) =1a(2) =-4a(3) =-19a(4) =-48a(5) =-93a(6) =-152a(7) =-215a(8) =-256a(9) =-217a(10) =24a(11) =717a(12) =2368a(13) =5995a(14) =13640a(15) =29393a(16) =61440a(17) =126159a(18) =256312a(19) =517429a(20) =1040576a(21) =2087891a(22) =4183656a(23) =8376441a(24) =16763392a(25) =33538807a(26) =67091288a(27) =134198045a(28) =268413504a(29) =536846523