a(n) = (2*prime(n)^2 + 1)/3.

Terms

a(0) =17a(1) =33a(2) =81a(3) =113a(4) =193a(5) =241a(6) =353a(7) =561a(8) =641a(9) =913a(10) =1121a(11) =1233a(12) =1473a(13) =1873a(14) =2321a(15) =2481a(16) =2993a(17) =3361a(18) =3553a(19) =4161a(20) =4593a(21) =5281a(22) =6273a(23) =6801a(24) =7073a(25) =7633a(26) =7921a(27) =8513a(28) =10753a(29) =11441