a(n) = 7*n^3 - 6*n^2.

Terms

a(0) =1a(1) =32a(2) =135a(3) =352a(4) =725a(5) =1296a(6) =2107a(7) =3200a(8) =4617a(9) =6400a(10) =8591a(11) =11232a(12) =14365a(13) =18032a(14) =22275a(15) =27136a(16) =32657a(17) =38880a(18) =45847a(19) =53600a(20) =62181a(21) =71632a(22) =81995a(23) =93312a(24) =105625a(25) =118976a(26) =133407a(27) =148960a(28) =165677a(29) =183600