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A052080
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Concatenation of n consecutive descending numbers starting from a(n) produces the smallest possible prime of this form, 0 if no such prime exists.
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3
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2, 4, 0, 10, 7, 0, 73, 46, 0, 56, 219, 0, 25, 60, 0, 52, 117, 0, 535, 172, 0
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OFFSET
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1,1
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COMMENTS
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First hard cases occur for n = 22, 88 and 110.
a(88) = 10^14 + 6.
a(110) = 10^19 + 26 was found by Chris Nash.
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LINKS
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EXAMPLE
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For n = 8 we have a(8) = 46 so the eight consecutive descending numbers 46,45,44,43,42,41,40 and 39 concatenated together gives the smallest possible prime of this form, 4645444342414039.
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CROSSREFS
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KEYWORD
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nonn,base,hard
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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