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A322655
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Numerator of (Sum_{d|n} sigma(d)) / sigma(n).
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3
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1, 4, 5, 11, 7, 5, 9, 26, 18, 14, 13, 55, 15, 3, 35, 57, 19, 24, 21, 11, 45, 13, 25, 13, 38, 10, 29, 99, 31, 35, 33, 40, 65, 38, 21, 198, 39, 7, 75, 91, 43, 15, 45, 143, 21, 25, 49, 285, 22, 152, 95, 165, 55, 29, 91, 39, 21, 62, 61, 55, 63, 11, 81, 247, 5, 65
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OFFSET
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1,2
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COMMENTS
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Also numerator of Sum_{d|n} (sigma(d) / sigma(n)).
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LINKS
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FORMULA
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EXAMPLE
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For n = 4; a(4) = numerator((Sum_{d|4} sigma(d)) / sigma(4)) = numerator((1 + 3 + 7) / (1 + 2 + 4)) = numerator(11/7) = 11.
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MATHEMATICA
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Table[Numerator[Sum[DivisorSigma[1, d], {d, Divisors[n]}] / DivisorSigma[1, n]], {n, 1, 100}] (* Vaclav Kotesovec, Dec 22 2018 *)
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PROG
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(Magma) [Numerator(&+[SumOfDivisors(d): d in Divisors(n)] / SumOfDivisors(n)): n in [1..1000]]
(PARI) a(n) = numerator(sumdiv(n, d, sigma(d))/sigma(n)); \\ Michel Marcus, Dec 22 2018
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CROSSREFS
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KEYWORD
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nonn,frac
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AUTHOR
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STATUS
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approved
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