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A105869
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Numbers k such that sigma(k) == 10 (mod k).
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0
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OFFSET
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1,2
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COMMENTS
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9671406556892844141838336 is a term (as are all numbers of the form 2^(j-1)*(2^j - 11) where 2^j - 11 is prime). - Jon E. Schoenfield, Jun 02 2019
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LINKS
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EXAMPLE
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Sigma(40) = 90 == 10 (mod 40).
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MATHEMATICA
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Join[{1}, Select[Range[600000], Mod[DivisorSigma[1, #], #]==10 &]] (* Vincenzo Librandi, Mar 11 2014 *)
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CROSSREFS
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KEYWORD
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more,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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