a(n) = (n^2+n+1)*(n^2+n)*n^2.

Terms

a(0) =0a(1) =6a(2) =168a(3) =1404a(4) =6720a(5) =23250a(6) =65016a(7) =156408a(8) =336384a(9) =663390a(10) =1221000a(11) =2124276a(12) =3526848a(13) =5628714a(14) =8684760a(15) =13014000a(16) =19009536a(17) =27149238a(18) =38007144a(19) =52265580a(20) =70728000a(21) =94332546a(22) =124166328a(23) =161480424a(24) =207705600a(25) =264468750a(26) =333610056a(27) =417200868a(28) =517562304