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A157200
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Numbers k such that k*(2k)^k - 1 is a prime.
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0
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2, 3, 6, 7, 12, 21, 113, 404, 735, 1944, 4973
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internal format)
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OFFSET
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1,1
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COMMENTS
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Conjecture: there are infinitely many such primes.
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LINKS
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EXAMPLE
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2*(2*2)^2 - 1 = 31 is prime, so 2 is a term;
3^(2*3)^2 - 1 = 107 is prime, so 3 is a term.
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MATHEMATICA
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Do[cp=n*(2*n)^n-1; If[PrimeQ[cp], Print[n]], {n, 1, 2000}] (* generates the first 10 terms *)
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PROG
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CROSSREFS
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KEYWORD
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hard,nice,nonn,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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