a(n) = (3*n-1) * 3*n * (3*n+1).

Terms

a(0) =24a(1) =210a(2) =720a(3) =1716a(4) =3360a(5) =5814a(6) =9240a(7) =13800a(8) =19656a(9) =26970a(10) =35904a(11) =46620a(12) =59280a(13) =74046a(14) =91080a(15) =110544a(16) =132600a(17) =157410a(18) =185136a(19) =215940a(20) =249984a(21) =287430a(22) =328440a(23) =373176a(24) =421800a(25) =474474a(26) =531360a(27) =592620a(28) =658416a(29) =728910