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Search: id:A090534
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| A090534 |
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Least n-digit prime in which every two digit string is also a prime, or 0 if no such number exists. ((n-1) two digit string primes occur.). |
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+0
1
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| 2, 11, 113, 1117, 11113, 111119, 1111379, 11111117, 111111113, 1111111973, 11111111113, 111111111379, 1111111111717, 11111111111719, 111111111111713, 1111111111111319, 11111111111111119, 111111111111111131
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OFFSET
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2,1
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COMMENT
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Conjecture: sequence is infinite. Note:(1); If n==1 (mod 3) then in most cases a(n) is a permutation of (n-1), 1's and a 7, else a(n) is a digit permutation of (n-1) ones and a 3. (2): Obviously all the digits except the most significant one must be odd.
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EXAMPLE
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a(5) =11113 in which 11,11,11,13 are the two digit string primes.
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CROSSREFS
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Sequence in context: A098437 A145163 A069574 this_sequence A130222 A057076 A118794
Adjacent sequences: A090531 A090532 A090533 this_sequence A090535 A090536 A090537
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KEYWORD
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base,nonn
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AUTHOR
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Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Dec 08 2003
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EXTENSIONS
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More terms from David Wasserman (wasserma(AT)spawar.navy.mil), Dec 21 2005
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