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A032418
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Numbers n such that 137 * 2^n + 1 is a prime.
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2
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3, 27, 39, 83, 203, 395, 467, 875, 1979, 6939, 13623, 22835, 56307, 81839, 197783, 224879, 261147, 523283, 533043, 2457639
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OFFSET
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1,1
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LINKS
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EXAMPLE
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137 * 2^3 + 1 = 1097 is a prime so 3 is in the sequence.
137 * 2^5 + 1 = 4385 = 5 * 877, so 5 is not in the sequence.
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MATHEMATICA
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Select[Range[1000], PrimeQ[137 2^# + 1] &] (* Alonso del Arte, Apr 06 2020 *)
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CROSSREFS
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KEYWORD
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nonn,hard
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AUTHOR
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EXTENSIONS
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3 more terms sent by Jud McCranie, Jan 15 2000 and May 03 2000
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STATUS
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approved
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