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A076730
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Maximum number of (distinct) primes that an n-digit number may shelter (i.e., primes contained among all digital substrings' permutations).
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6
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1, 4, 11, 31, 106, 402, 1953, 10542, 64905, 362451, 2970505
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OFFSET
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1,2
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COMMENTS
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See sequence A134596 for the least numbers of given length which yields these maxima over n-digit indices for A039993. - M. F. Hasler, Mar 11 2014
By definition this is a subsequence of A076497. The term a(10) was incorrectly given as 398100 = A075053(1123456789), which double-counts each prime using only one digit '1'. But a(10) = A039993(1123456789) = A076497(80) = 362451. The values given for a(9) and a(11) were also incorrect, the latter probably for the same reason, and for a(9) probably due to double-counting of primes with leading zeros. - M. F. Hasler and David A. Corneth, Oct 15 2019
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LINKS
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FORMULA
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EXAMPLE
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We have a(3)=11, since among numbers 100 through 999, the smallest ones having 5, 6, 7, 8, 10, 11 embedded primes are respectively 107, 127, 113, 167, 179, 137 (the last of these being the first reaching the maximum number of 11 embedded primes, viz. 3, 7, 13, 17, 31, 37, 71, 73, 137, 173, 317).
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PROG
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(Python) # see linked program in A076449
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CROSSREFS
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KEYWORD
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hard,more,base,nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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