a(n) = 4*n^2 - 4*n + 19, n >= 1.

Terms

a(0) =19a(1) =27a(2) =43a(3) =67a(4) =99a(5) =139a(6) =187a(7) =243a(8) =307a(9) =379a(10) =459a(11) =547a(12) =643a(13) =747a(14) =859a(15) =979a(16) =1107a(17) =1243a(18) =1387a(19) =1539a(20) =1699a(21) =1867a(22) =2043a(23) =2227a(24) =2419a(25) =2619a(26) =2827a(27) =3043a(28) =3267a(29) =3499