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A319245
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Numbers k such that k^2 + 1 divides 2^k + 8.
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0
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0, 1, 17, 37, 77, 197, 513, 993, 1837, 2617, 2637, 4097, 5437, 65537, 261633, 364137, 437837, 2097153, 16777217, 32761917, 54644032237, 68719476737, 137438953473, 1099511627777
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OFFSET
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1,3
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COMMENTS
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Prime terms are 17, 37, 197, 2617, 5437, 65537, 437837, ...
Numbers t such that 2^t + 1 is a term are 4, 9, 12, 16, 21, 24, 36, 37, 40, 45, 49, 52, 57, 64, 69, 76, 84, 96, ...
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LINKS
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MATHEMATICA
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Select[Range[0, 9999], Divisible[2^# + 8, #^2 + 1] &] (* Alonso del Arte, Sep 16 2018 *)
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PROG
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(PARI) isok(n)=Mod(2, n^2+1)^n==-8;
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CROSSREFS
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KEYWORD
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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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