Numbers k such that k and 8*k + 1 are both prime.

Terms

a(0) =2a(1) =5a(2) =11a(3) =17a(4) =29a(5) =71a(6) =101a(7) =107a(8) =131a(9) =137a(10) =149a(11) =179a(12) =239a(13) =269a(14) =347a(15) =401a(16) =431a(17) =449a(18) =479a(19) =491a(20) =509a(21) =557a(22) =599a(23) =617a(24) =659a(25) =677a(26) =761a(27) =809a(28) =821a(29) =857