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A112992
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Numbers k such that ceiling(2^(2^k mod k)/3) is odd.
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0
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1, 2, 4, 8, 16, 25, 32, 45, 55, 64, 91, 95, 99, 125, 128, 135, 143, 153, 155, 161, 175, 187, 225, 235, 245, 247, 256, 261, 273, 275, 279, 285, 289, 297, 319, 329, 333, 335, 355, 363, 369, 387, 391, 403, 407, 413, 423, 425, 429, 435, 437, 441, 459, 473, 477, 481, 483, 493
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OFFSET
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1,2
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COMMENTS
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Conjecture: the odd values of ceiling(2^(2^k mod k)/3) are Jacobsthal numbers (and the even values are 1 plus a Jacobsthal number).
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LINKS
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MATHEMATICA
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Select[Range[493], OddQ[Ceiling[2^PowerMod[2, #, #]/3]]&] (* James C. McMahon, Jun 14 2024 *)
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PROG
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(PARI) isok(k) = (ceil(2^lift(Mod(2, k)^k)/3) % 2) == 1; \\ Michel Marcus, Jun 14 2024
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CROSSREFS
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KEYWORD
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easy,nonn
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AUTHOR
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STATUS
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approved
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