a(n) = 2^n-n^5.

Terms

a(0) =1a(1) =1a(2) =-28a(3) =-235a(4) =-1008a(5) =-3093a(6) =-7712a(7) =-16679a(8) =-32512a(9) =-58537a(10) =-98976a(11) =-159003a(12) =-244736a(13) =-363101a(14) =-521440a(15) =-726607a(16) =-983040a(17) =-1288785a(18) =-1627424a(19) =-1951811a(20) =-2151424a(21) =-1986949a(22) =-959328a(23) =1952265a(24) =8814592a(25) =23788807a(26) =55227488a(27) =119868821a(28) =251225088