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A066811
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Numbers n such that concatenation of odd numbers from 1 to n is a prime.
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1
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OFFSET
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1,1
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LINKS
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Table of n, a(n) for n=1..6.
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EXAMPLE
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E.g. a(2)=19 because 135791113151719 is a prime.
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MATHEMATICA
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p = ""; Do[p = p <> ToString[2*n+1]; If[PrimeQ[ToExpression[p]], Print[2*n+1]], {n, 0, 2569}] (Propper)
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CROSSREFS
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Cf. A005408, A000040.
Sequence in context: A218537 A222590 A107165 * A162307 A128069 A056246
Adjacent sequences: A066808 A066809 A066810 * A066812 A066813 A066814
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KEYWORD
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base,nonn
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AUTHOR
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Patrick De Geest, Jan 20 2002
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EXTENSIONS
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5139 from Ryan Propper (rpropper(AT)stanford.edu), Aug 26 2005
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STATUS
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approved
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