a(n) = n^5 - 1.

Terms

a(0) =0a(1) =31a(2) =242a(3) =1023a(4) =3124a(5) =7775a(6) =16806a(7) =32767a(8) =59048a(9) =99999a(10) =161050a(11) =248831a(12) =371292a(13) =537823a(14) =759374a(15) =1048575a(16) =1419856a(17) =1889567a(18) =2476098a(19) =3199999a(20) =4084100a(21) =5153631a(22) =6436342a(23) =7962623a(24) =9765624a(25) =11881375a(26) =14348906a(27) =17210367a(28) =20511148a(29) =24299999