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A276200
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Largest prime < the concatenation of the numbers from 1 to n (A007908).
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0
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11, 113, 1231, 12343, 123449, 1234547, 12345653, 123456761, 12345678899, 1234567891003, 123456789101099, 12345678910111207, 1234567891011121309, 123456789101112131383, 12345678910111213141337, 1234567891011121314151561, 123456789101112131415161717, 12345678910111213141516171723
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OFFSET
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2,1
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COMMENTS
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LINKS
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FORMULA
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EXAMPLE
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a(5) = 12343, because this is the largest prime less than 12345.
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MATHEMATICA
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Table[NextPrime[FromDigits[Flatten[IntegerDigits[Range[n]]]], -1], {n, 2, 19}]
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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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