a(n) = 38*n^2 - 1.

Terms

a(0) =37a(1) =151a(2) =341a(3) =607a(4) =949a(5) =1367a(6) =1861a(7) =2431a(8) =3077a(9) =3799a(10) =4597a(11) =5471a(12) =6421a(13) =7447a(14) =8549a(15) =9727a(16) =10981a(17) =12311a(18) =13717a(19) =15199a(20) =16757a(21) =18391a(22) =20101a(23) =21887a(24) =23749a(25) =25687a(26) =27701a(27) =29791a(28) =31957a(29) =34199