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

Terms

a(0) =0a(1) =6a(2) =48a(3) =180a(4) =480a(5) =1050a(6) =2016a(7) =3528a(8) =5760a(9) =8910a(10) =13200a(11) =18876a(12) =26208a(13) =35490a(14) =47040a(15) =61200a(16) =78336a(17) =98838a(18) =123120a(19) =151620a(20) =184800a(21) =223146a(22) =267168a(23) =317400a(24) =374400a(25) =438750a(26) =511056a(27) =591948a(28) =682080a(29) =782130