Primes whose digits are primes; primes having only {2, 3, 5, 7} as digits.

Terms

a(0) =2a(1) =3a(2) =5a(3) =7a(4) =23a(5) =37a(6) =53a(7) =73a(8) =223a(9) =227a(10) =233a(11) =257a(12) =277a(13) =337a(14) =353a(15) =373a(16) =523a(17) =557a(18) =577a(19) =727a(20) =733a(21) =757a(22) =773a(23) =2237a(24) =2273a(25) =2333a(26) =2357a(27) =2377a(28) =2557a(29) =2753