a(n) = 4*(n - 1)*(16*n - 23) for n >= 1.

Terms

a(0) =0a(1) =36a(2) =200a(3) =492a(4) =912a(5) =1460a(6) =2136a(7) =2940a(8) =3872a(9) =4932a(10) =6120a(11) =7436a(12) =8880a(13) =10452a(14) =12152a(15) =13980a(16) =15936a(17) =18020a(18) =20232a(19) =22572a(20) =25040a(21) =27636a(22) =30360a(23) =33212a(24) =36192a(25) =39300a(26) =42536a(27) =45900a(28) =49392a(29) =53012