a(n) = 16*n^2 + 2*n.

Terms

a(0) =18a(1) =68a(2) =150a(3) =264a(4) =410a(5) =588a(6) =798a(7) =1040a(8) =1314a(9) =1620a(10) =1958a(11) =2328a(12) =2730a(13) =3164a(14) =3630a(15) =4128a(16) =4658a(17) =5220a(18) =5814a(19) =6440a(20) =7098a(21) =7788a(22) =8510a(23) =9264a(24) =10050a(25) =10868a(26) =11718a(27) =12600a(28) =13514a(29) =14460