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A087367
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Twin primes whose digits are primes.
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0
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3, 5, 227, 2237, 3257, 3527, 3557, 7757, 22277, 23537, 25577, 27527, 27737, 37337, 55337, 57527, 57557, 72227, 77237, 223337, 223757, 225527, 233327, 272537, 277577, 327557, 327737, 337277, 357737, 375257, 377327, 522227, 525377, 553277
(list; graph; refs; listen; history; internal format)
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OFFSET
| 3,1
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COMMENTS
| Except for 3 and 5 these numbers must end in 7. If twin primes are infinite can we prove these numbers are infinite?
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PROG
| (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", ")); ) ) }
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CROSSREFS
| Sequence in context: A104996 A175133 A012817 * A058846 A101331 A087368
Adjacent sequences: A087364 A087365 A087366 * A087368 A087369 A087370
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KEYWORD
| easy,nonn,base
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AUTHOR
| Cino Hilliard (hillcino368(AT)gmail.com), Oct 21 2003
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