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A216551
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Numbers n such that (2^n+1)/3 is prime, but cannot be written in the form a^2 + 3*b^2.
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0
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5, 11, 17, 23, 101, 167, 191, 347, 701, 1709, 3539, 5807, 10691, 11279, 42737, 83339, 95369, 117239, 127031, 267017, 269987, 374321, 4031399
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OFFSET
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1,1
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COMMENTS
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The exponent is congruent to 2 mod 3.
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LINKS
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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