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A262555
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Numbers n such that the concatenation of the decimal numbers 1 through n, but omitting 2, is a prime.
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2
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OFFSET
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1,1
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COMMENTS
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The corresponding primes are the primes in A262572. Probabilistic arguments suggest the sequence is infinite.
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LINKS
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EXAMPLE
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The first two terms correspond to the primes 13 and 134567891011121314151617181920212223242526272829303132333435363738394041 (see A262298).
a(3) corresponds to a prime ending in 103, with 200 digits, a(4) to a probable prime ending in 1713, with 5744 digits, and a(5) to a probable prime ending in 2769, with 9968 digits. These three terms were found by David Broadhurst on Oct 09 2015.
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CROSSREFS
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KEYWORD
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nonn,base,more
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AUTHOR
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STATUS
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approved
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