Numbers k such that (k^2 + 1)/2 is prime.

Terms

a(0) =3a(1) =5a(2) =9a(3) =11a(4) =15a(5) =19a(6) =25a(7) =29a(8) =35a(9) =39a(10) =45a(11) =49a(12) =51a(13) =59a(14) =61a(15) =65a(16) =69a(17) =71a(18) =79a(19) =85a(20) =95a(21) =101a(22) =121a(23) =131a(24) =139a(25) =141a(26) =145a(27) =159a(28) =165a(29) =169