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A099008
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Numbers n such that the denominator of the 2n-th Bernoulli number is divisible by n but sum_{d|n} sigma(d)/phi(d) is not an integer.
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0
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546, 903, 1806, 2730, 6162, 6510, 9030, 10230, 12090, 12246, 12810, 15834, 20130, 20670, 23478, 23790, 28938, 30030, 30810, 43134, 44310, 52374, 56730, 61230, 71610, 79170, 84630, 85722, 88410, 99330, 109230, 117390, 132990, 140910, 144690, 154770, 164010
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OFFSET
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1,1
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COMMENTS
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LINKS
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EXAMPLE
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The denominator of the 1806th Bernoulli number is 1806 and Sum_{d|1806} sigma(d)/phi(d) = 172/3 is not an integer.
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PROG
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(PARI) lista() = {v = readvec("b106741.txt"); for (i=1, #v, vi = v[i]; if (denominator(sumdiv(vi, d, sigma(d)/eulerphi(d))) != 1, print1(vi, ", "))); } \\ Michel Marcus, Dec 07 2013
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CROSSREFS
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KEYWORD
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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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