Numbers of the form (4k+3)^2+4 or (4k+5)^2-8.

Terms

a(0) =13a(1) =17a(2) =53a(3) =73a(4) =125a(5) =161a(6) =229a(7) =281a(8) =365a(9) =433a(10) =533a(11) =617a(12) =733a(13) =833a(14) =965a(15) =1081a(16) =1229a(17) =1361a(18) =1525a(19) =1673a(20) =1853a(21) =2017a(22) =2213a(23) =2393a(24) =2605a(25) =2801a(26) =3029a(27) =3241a(28) =3485a(29) =3713