Numbers k such that k prefixed by '6' and followed by '9' is a prime.

Terms

a(0) =1a(1) =5a(2) =19a(3) =22a(4) =26a(5) =29a(6) =32a(7) =35a(8) =37a(9) =38a(10) =44a(11) =46a(12) =52a(13) =56a(14) =59a(15) =61a(16) =65a(17) =67a(18) =68a(19) =70a(20) =71a(21) =77a(22) =82a(23) =86a(24) =89a(25) =94a(26) =95a(27) =109a(28) =112a(29) =116