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A155048
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Primes n such that number of prime digits of prime(n) = number of nonprime digits of prime(n).
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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
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| Prime digit = 2, 3, 5 or 7. Nonprime digit = 0, 1, 4, 6, 8 or 9.
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EXAMPLE
| If n=7=prime and 17=prime(7), then 1(1)=1(7) and 7=a(1). If n=11=prime and 31=prime(11), then 1(3)=1(1) and 11=a(2). If n=19=prime and 67=prime(19(, then 1(6)=1(7) and 19=a(3). If n=23=prime and 83=prime(23), then 1(8)=1(3) and 23=a(4). If n=191=prime and 1153=prime(191), then 2(1 and 1)=2(5 and 3) and 191=a(4), etc.
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CROSSREFS
| Cf. A000040, A141468.
Sequence in context: A019365 A191055 A078497 * A063639 A131229 A092737
Adjacent sequences: A155045 A155046 A155047 * A155049 A155050 A155051
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KEYWORD
| nonn,base
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AUTHOR
| Juri-Stepan Gerasimov (2stepan(AT)rambler.ru), Jan 19 2009
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EXTENSIONS
| Corrected (17 and 479 inserted) by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), May 05 2010
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