a(n) = n^4 + 3*n^3 + 2*n^2 - 2*n.

Terms

a(0) =0a(1) =4a(2) =44a(3) =174a(4) =472a(5) =1040a(6) =2004a(7) =3514a(8) =5744a(9) =8892a(10) =13180a(11) =18854a(12) =26184a(13) =35464a(14) =47012a(15) =61170a(16) =78304a(17) =98804a(18) =123084a(19) =151582a(20) =184760a(21) =223104a(22) =267124a(23) =317354a(24) =374352a(25) =438700a(26) =511004a(27) =591894a(28) =682024a(29) =782072