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A230238
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Numbers n such that phi(sigma(n)) + sigma(phi(n)) is the mean value of phi(n) and sigma(n).
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2
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6, 37716, 58710, 120930, 1269432, 2663850, 3349170, 3995244, 4353426, 5468424, 7191072, 7437960, 7564128, 7613892, 8354610, 8810490, 10309410, 11917620, 13573500, 21970980, 23877450, 24712350, 38801790, 49394556, 56208264, 56809578, 57339150, 66379170, 77966616, 91549710, 93657564
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OFFSET
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1,1
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LINKS
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MATHEMATICA
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Do[If[DivisorSigma[1, n]+EulerPhi[n]==2(EulerPhi[DivisorSigma[1, n]]+DivisorSigma[1, EulerPhi[n]]), Print[n]], {n, 100000000}]
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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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