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A155048
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Primes p such that number of prime digits of prime(p) = number of nonprime digits of prime(p).
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0
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7, 11, 17, 19, 23, 191, 199, 211, 227, 251, 277, 281, 311, 337, 347, 353, 359, 373, 383, 389, 397, 401, 409, 419, 439, 463, 467, 479, 523, 547, 557, 569, 571, 577, 593, 599, 613, 619, 641, 643, 653, 659, 673, 677, 683, 701, 709, 743, 751, 757, 769, 787, 809
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OFFSET
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1,1
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COMMENTS
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Prime digits are 2, 3, 5 or 7, nonprime digit are 0, 1, 4, 6, 8 or 9.
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LINKS
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PROG
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(PARI) f(n) = #select(isprime, digits(prime(n))); \\ A109066
isok(p) = my(nbp=f(prime(p))); isprime(p) && (2*f(p) == #digits(prime(p))); \\ Michel Marcus, Feb 18 2021
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CROSSREFS
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KEYWORD
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nonn,base,less
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AUTHOR
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EXTENSIONS
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Corrected (17 and 479 inserted) by R. J. Mathar, May 05 2010
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STATUS
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approved
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