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A265713
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Numbers k such that floor(Sum_{d|k} 1 / sigma(d)) = 3.
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9
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110880, 166320, 221760, 277200, 327600, 332640, 360360, 388080, 393120, 415800, 443520, 471240, 480480, 491400, 498960, 526680, 540540, 554400, 556920, 582120, 589680, 600600, 622440, 637560, 655200, 665280, 693000, 720720, 776160, 786240, 803880, 831600
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OFFSET
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1,1
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COMMENTS
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See A265714(n) = the smallest number k such that floor(Sum_{d|k} 1/sigma(d)) = n.
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LINKS
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EXAMPLE
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110880 is a term because floor(Sum_{d|110880} 1/sigma(d)) = floor(22333/7440) = 3.
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MATHEMATICA
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Select[Range[10^5, 9*10^5], Floor[Sum[1/DivisorSigma[1, d], {d, Divisors@ #}]] == 3 &] (* Michael De Vlieger, Dec 31 2015 *)
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PROG
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(Magma) [n: n in [1..1000000] | Floor(&+[1/SumOfDivisors(d): d in Divisors(n)]) eq 3]
(PARI) isok(n) = floor(sumdiv(n, d, 1/sigma(d))) == 3; \\ Michel Marcus, Dec 27 2015
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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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