a(n) = n^3 - 1.

Terms

a(0) =0a(1) =7a(2) =26a(3) =63a(4) =124a(5) =215a(6) =342a(7) =511a(8) =728a(9) =999a(10) =1330a(11) =1727a(12) =2196a(13) =2743a(14) =3374a(15) =4095a(16) =4912a(17) =5831a(18) =6858a(19) =7999a(20) =9260a(21) =10647a(22) =12166a(23) =13823a(24) =15624a(25) =17575a(26) =19682a(27) =21951a(28) =24388a(29) =26999