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A220120
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Bases having a record-sized smallest prime such that there are two smaller primes with which all 6 ways of juxtaposition in the base are prime.
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1
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2, 7, 12, 18, 20, 24, 26, 29, 41, 53, 72, 107, 137, 152, 158, 314, 1007, 1097, 1763
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OFFSET
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1,1
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COMMENTS
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Ties occur with bases 13 and 1553, which are detailed in the EXAMPLE section for completeness. See A220121 for the rest of the data.
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LINKS
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EXAMPLE
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In base 13, for any triple of primes under 103--the record corresponding to a(3)=12--at least 1 of the ways of stringing the primes together gives a composite; but {11,73,103} is a set giving primes all 6 ways: In base 13, these 3 primes are written B, 58 and 7C; and {587CB, 58B7C, 7C58B, 7CB58, B587C, B7C58} in base 13 corresponds to decimal {161731, 162343, 227251, 228223, 326611, 331651} (all of which are prime).
Base 1553 also ties the record set by base a(18)=1097, with no triple of primes under 1061 giving just primes, while the triple {197, 911, 1061} does.
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CROSSREFS
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KEYWORD
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nonn,base
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AUTHOR
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STATUS
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approved
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