Largest prime all of whose substrings in its base n representation are primes.

Terms

a(0) =2a(1) =11a(2) =67a(3) =23a(4) =37a(5) =491a(6) =47a(7) =373a(8) =79a(9) =6043a(10) =379a(11) =2203a(12) =647a(13) =3389a(14) =631a(15) =34807a(16) =211a(17) =28663a(18) =1283a(19) =6449a(20) =439a(21) =266003a(22) =577a(23) =15649a(24) =1811a(25) =244471a(26) =379a(27) =485504623a(28) =157a(29) =31907