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A057195
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Numbers k such that 2^k + 7 is prime.
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26
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2, 4, 6, 8, 10, 16, 18, 20, 28, 30, 38, 44, 78, 88, 98, 126, 160, 174, 204, 214, 588, 610, 798, 926, 1190, 1198, 1806, 1888, 2648, 3454, 3510, 3864, 3870, 8970, 12330, 13330, 18876, 22338, 39718, 55006, 110784, 172470, 196434, 235710, 247280, 268408, 279320, 300874, 315268, 372950, 472258, 566496, 780284, 820356
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OFFSET
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1,1
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COMMENTS
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Naturally all terms are even because (3-1)^(2n+1)+7 is divisible by 3. - Bruno Berselli, Oct 03 2012
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LINKS
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FORMULA
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MAPLE
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MATHEMATICA
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Do[ If[ PrimeQ[ 2^n +7 ], Print[n]], { n, 1, 15000 }]
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PROG
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CROSSREFS
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Cf. A104066 (primes of the form 2^k+7).
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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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