Twin primes whose digits are primes.

Terms

a(0) =3a(1) =5a(2) =227a(3) =2237a(4) =3257a(5) =3527a(6) =3557a(7) =7757a(8) =22277a(9) =23537a(10) =25577a(11) =27527a(12) =27737a(13) =37337a(14) =55337a(15) =57527a(16) =57557a(17) =72227a(18) =77237a(19) =223337a(20) =223757a(21) =225527a(22) =233327a(23) =272537a(24) =277577a(25) =327557a(26) =327737a(27) =337277a(28) =357737a(29) =375257