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A201363
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Numbers k such that (2^k - k - 1)*2^k - 1 is prime.
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7
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OFFSET
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1,1
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COMMENTS
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No further terms less than 10000. - T. D. Noe, Nov 30 2011
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LINKS
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EXAMPLE
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7 is in the sequence because (2^7 - 7 - 1)*2^7 - 1 = 15359 is prime.
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MATHEMATICA
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lst={}; Do[If[PrimeQ[(2^n - n-1)*2^n-1], AppendTo[lst, n]], {n, 15000}]; lst
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PROG
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CROSSREFS
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KEYWORD
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nonn,hard,more
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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