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A091909
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Numbers n such that (2*n)!/(2*n!)+1 is prime.
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1
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1, 2, 3, 5, 6, 11, 12, 36, 95, 372, 842, 2196, 4755
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OFFSET
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1,2
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COMMENTS
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LINKS
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EXAMPLE
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a(3)=3 because (2*3)!/(2*3!)+1=720/12+1=61 is prime.
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CROSSREFS
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KEYWORD
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nonn,more,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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