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Search: id:A155054
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| A155054 |
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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
1
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| 5, 13, 29, 41, 43, 47, 53, 79, 83, 89, 97, 109, 113, 127, 149, 157, 163, 167, 173, 179, 181, 193, 197, 223, 229, 233, 239, 257, 263, 271, 277, 283, 293, 313, 379, 419, 421, 431, 433, 443, 449, 487, 541, 563, 601, 607, 617, 631, 647, 661, 691, 719, 761, 773
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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Prime digit = 2, 3, 5 or 7. Nonprime digit = 0, 1, 4, 6, 8 or 9.
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FORMULA
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If n=5=prime and 11=prime(5), then 0<2(1 and 1) and 5=a(1). If n=13=prime and 41=prime(13), then 0<2(4 and 1) and 13=a(2). If n=29=prime and 109=prime(23), then 0<3(1, 0 and 9) and 29=a(3). If n=41=prime and 179=prime(41), then 1(7)<(1 and 9) and 41=a(4), etc.
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EXAMPLE
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If n=41=prime and 179=prime(41), then 1(7)<2(1 and 9) and 41=a(4). If n=43=prime and 191=prime(43), then 0<3(1, 9 and 1) and 43=a(5). If n=47=prime and 211=prime(47), then 1(2)<2(1 and 1) and 47=a(6), etc.
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CROSSREFS
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Cf. A000040, A141468.
Sequence in context: A100877 A007521 A078598 this_sequence A158756 A159351 A163251
Adjacent sequences: A155051 A155052 A155053 this_sequence A155055 A155056 A155057
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KEYWORD
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nonn,base
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AUTHOR
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Juri-Stepan Gerasimov (2stepan(AT)rambler.ru), Jan 19 2009
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