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%I #5 Oct 01 2013 17:57:43
%S 3,5,227,2237,3257,3527,3557,7757,22277,23537,25577,27527,27737,37337,
%T 55337,57527,57557,72227,77237,223337,223757,225527,233327,272537,
%U 277577,327557,327737,337277,357737,375257,377327,522227,525377,553277
%N Twin primes whose digits are primes.
%C Except for 3 and 5 these numbers must end in 7. If twin primes are infinite can we prove these numbers are infinite?
%o (PARI) pdigitp(n) = { forprime(x=2,n, flag=1; y=x; if(isprime(x+2), for(j=1,length(Str(y)), r = y%10; if(!isprime(r),flag=0); y = floor(y/10); ); if(flag,print1(x",")); ) ) }
%K easy,nonn,base
%O 3,1
%A _Cino Hilliard_, Oct 21 2003
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