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A232703
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Numbers k that divide sigma(k) + sigma(k^2).
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3
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OFFSET
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1,2
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COMMENTS
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LINKS
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MATHEMATICA
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Select[Range[150000], Mod[Plus @@ DivisorSigma[1, {#, #^2}], #] == 0 &] (* Giovanni Resta, Jun 10 2016 *)
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CROSSREFS
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Cf. A000203 (sigma(n) = sum of divisors of n).
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KEYWORD
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nonn,hard,more
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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