Digit '3' concatenated with a(n) is a prime.

Terms

a(0) =1a(1) =7a(2) =11a(3) =13a(4) =17a(5) =31a(6) =37a(7) =47a(8) =49a(9) =53a(10) =59a(11) =67a(12) =73a(13) =79a(14) =83a(15) =89a(16) =97a(17) =109a(18) =119a(19) =121a(20) =137a(21) =163a(22) =167a(23) =169a(24) =181a(25) =187a(26) =191a(27) =203a(28) =209a(29) =217