Numbers k such that k prefixed by '7' and followed by '1' is prime.

Terms

a(0) =0a(1) =5a(2) =6a(3) =12a(4) =15a(5) =21a(6) =32a(7) =33a(8) =35a(9) =41a(10) =45a(11) =48a(12) =54a(13) =56a(14) =59a(15) =62a(16) =68a(17) =69a(18) =74a(19) =84a(20) =90a(21) =95a(22) =101a(23) =108a(24) =116a(25) =117a(26) =119a(27) =126a(28) =134a(29) =141