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

Terms

a(0) =0a(1) =-1a(2) =2a(3) =15a(4) =44a(5) =95a(6) =174a(7) =287a(8) =440a(9) =639a(10) =890a(11) =1199a(12) =1572a(13) =2015a(14) =2534a(15) =3135a(16) =3824a(17) =4607a(18) =5490a(19) =6479a(20) =7580a(21) =8799a(22) =10142a(23) =11615a(24) =13224a(25) =14975a(26) =16874a(27) =18927a(28) =21140a(29) =23519