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A073349
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Numbers n such that sigma(n)/n is equal to sigma(k)/k for some k being superabundant (A004394).
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0
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1, 2, 4, 6, 12, 24, 28, 36, 48, 60, 120, 180, 234, 240, 360, 496, 600, 672, 720, 840, 1170, 1260, 1680, 1800, 2016, 2520, 4200, 5040, 8128, 10080, 12600, 15120, 22320, 25200, 27000, 27720, 37800, 55440, 55800, 55860, 110880, 138600, 166320, 167580, 277200
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OFFSET
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1,2
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COMMENTS
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Previous name was: Numbers n such that sigma(k)/k < sigma(n)/n for k=1,2,3...,n-1.
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LINKS
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PROG
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(PARI) lista(nn) = {vs = Set(); maxs = 0; for(n = 1, nn, news = sigma(n, -1); if (news > maxs, maxs = news; print1(n, ", "); vs = Set(concat(vs, maxs)); , if (setsearch(vs, news), print1(n, ", ")); ); ); } \\ Michel Marcus, Dec 02 2013
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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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EXTENSIONS
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STATUS
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approved
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