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A348032
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Multiply-perfect numbers k that do not have a divisor d such that sigma(d)*d = k.
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1
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2178540, 45532800, 459818240, 1476304896, 14182439040, 31998395520, 43861478400, 51001180160, 518666803200, 704575228896, 13661860101120, 30823866178560, 181742883469056, 740344994887680, 796928461056000, 6088728021160320, 20158185857531904, 212517062615531520, 622286506811515392, 69357059049509038080, 87934476737668055040
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OFFSET
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1,1
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COMMENTS
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Question: Is A323653 a subsequence of this sequence? See also conjecture in A348033.
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LINKS
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MATHEMATICA
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With[{s = DeleteCases[Map[ToExpression[#] &, Import["https://oeis.org/A007691/b007691.txt", "Data"]], _?(Length[#] == 0 &)][[All, -1]]}, Select[s[[1 ;; 45]], Function[k, NoneTrue[Divisors[k], # DivisorSigma[1, #] == k &]]]] (* Michael De Vlieger, Sep 28 2021, using b-file at A007691 *)
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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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