a(n) = 4*n^3 + 5*n - 1.

Terms

a(0) =8a(1) =41a(2) =122a(3) =275a(4) =524a(5) =893a(6) =1406a(7) =2087a(8) =2960a(9) =4049a(10) =5378a(11) =6971a(12) =8852a(13) =11045a(14) =13574a(15) =16463a(16) =19736a(17) =23417a(18) =27530a(19) =32099a(20) =37148a(21) =42701a(22) =48782a(23) =55415a(24) =62624a(25) =70433a(26) =78866a(27) =87947a(28) =97700a(29) =108149