Prime worms.

Terms

a(0) =101a(1) =131a(2) =151a(3) =181a(4) =191a(5) =313a(6) =353a(7) =373a(8) =383a(9) =727a(10) =757a(11) =787a(12) =797a(13) =919a(14) =929a(15) =12101a(16) =14741a(17) =18181a(18) =32323a(19) =34543a(20) =35353a(21) =35753a(22) =72727a(23) =74747a(24) =75797a(25) =78787a(26) =79757a(27) =94949a(28) =95959a(29) =97579