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A069084
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Numbers n such that sigma(n)/tau(n) has denominator 5.
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1
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16, 48, 80, 81, 112, 176, 208, 240, 272, 336, 368, 405, 496, 528, 560, 567, 592, 624, 625, 656, 688, 720, 752, 784, 816, 848, 880, 891, 976, 1040, 1053, 1072, 1104, 1134, 1136, 1168, 1232, 1328, 1360, 1377, 1456, 1488, 1536, 1552, 1584, 1616, 1620, 1648
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OFFSET
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1,1
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LINKS
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FORMULA
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MATHEMATICA
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Select[Range[500], Denominator[DivisorSigma[1, #]/DivisorSigma[0, #]] == 5 &] (* Amiram Eldar, Sep 08 2019 *)
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PROG
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(Magma) [n:n in [1..1700]|Denominator(SumOfDivisors(n)/#Divisors(n)) eq 5]; // Marius A. Burtea, Sep 08 2019
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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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