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

Terms

a(0) =0a(1) =8a(2) =42a(3) =120a(4) =260a(5) =480a(6) =798a(7) =1232a(8) =1800a(9) =2520a(10) =3410a(11) =4488a(12) =5772a(13) =7280a(14) =9030a(15) =11040a(16) =13328a(17) =15912a(18) =18810a(19) =22040a(20) =25620a(21) =29568a(22) =33902a(23) =38640a(24) =43800a(25) =49400a(26) =55458a(27) =61992a(28) =69020a(29) =76560