a(n) = 1 - n^5.

Terms

a(0) =1a(1) =0a(2) =-31a(3) =-242a(4) =-1023a(5) =-3124a(6) =-7775a(7) =-16806a(8) =-32767a(9) =-59048a(10) =-99999a(11) =-161050a(12) =-248831a(13) =-371292a(14) =-537823a(15) =-759374a(16) =-1048575a(17) =-1419856a(18) =-1889567a(19) =-2476098a(20) =-3199999a(21) =-4084100a(22) =-5153631a(23) =-6436342a(24) =-7962623a(25) =-9765624a(26) =-11881375a(27) =-14348906a(28) =-17210367a(29) =-20511148