Palindromic primes = 1 mod 4.

Terms

a(0) =5a(1) =101a(2) =181a(3) =313a(4) =353a(5) =373a(6) =757a(7) =797a(8) =929a(9) =10301a(10) =10501a(11) =10601a(12) =12421a(13) =12721a(14) =12821a(15) =14341a(16) =14741a(17) =16061a(18) =16361a(19) =16561a(20) =16661a(21) =18181a(22) =18481a(23) =31013a(24) =31513a(25) =33533a(26) =35053a(27) =35153a(28) =35353a(29) =35753