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A121859
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Numbers n such that n!*3^n - 1 is prime.
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2
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1, 2, 12, 20, 38, 45, 46, 105, 117, 143, 214, 1835, 2931, 7703, 11542, 19225
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OFFSET
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1,2
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COMMENTS
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Corresponding primes of the form n!*3^n - 1 are a(n)!*3^a(n) - 1 ={2,17,254561089305599,8483004771271882804592639999,...}.
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LINKS
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MATHEMATICA
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Do[f=n!*3^n-1; If[PrimeQ[f], Print[{n, f}]], {n, 1, 25000}]
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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