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A215780
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Primes of the form 2*k!! - 1.
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2
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3, 5, 29, 1889, 20789, 270269, 15811707161249, 443286190953399543749, 433724868863888852244234239999, 163685683629861106170483229851647999999, 10144121732653119949813597183199268946575359999999, 67476497990875549413061344119283906281177486718749
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OFFSET
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1,1
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COMMENTS
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The corresponding k are in A215779.
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LINKS
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EXAMPLE
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29 = 2*5!! - 1 = 2*15 - 1 is in the sequence.
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MATHEMATICA
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a={}; Do[p= 2*n!! -1; If[PrimeQ[p], AppendTo[a, p]], {n, 0, 800}]; Print[a];
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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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