Emirps (primes whose reversal is a different prime).

Terms

a(0) =13a(1) =17a(2) =31a(3) =37a(4) =71a(5) =73a(6) =79a(7) =97a(8) =107a(9) =113a(10) =149a(11) =157a(12) =167a(13) =179a(14) =199a(15) =311a(16) =337a(17) =347a(18) =359a(19) =389a(20) =701a(21) =709a(22) =733a(23) =739a(24) =743a(25) =751a(26) =761a(27) =769a(28) =907a(29) =937