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A223609
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Numbers n whose abundance is 10. Sigma(n)-2*n = 10.
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5
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OFFSET
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1,1
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COMMENTS
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a(5) > 10^12.
Any term x of this sequence can be combined with any term y of A101223 to satisfy the property (sigma(x)+sigma(y))/(x+y) = 2, which is a necessary (but not sufficient) condition for two numbers to be amicable. - Timothy L. Tiffin, Sep 13 2016
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LINKS
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EXAMPLE
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n = 34358296576. sigma(n)-2*n = 10.
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MATHEMATICA
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Select[Range[1, 10^8], DivisorSigma[1, #] - 2 # == 10 &] (* Vincenzo Librandi, Sep 15 2016 *)
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PROG
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(PARI) for(n=1, 10^8, if(sigma(n)-2*n==10, print1(n ", ")))
(Magma) [n: n in [1..9*10^6] | (SumOfDivisors(n)-2*n) eq 10]; // Vincenzo Librandi, Sep 15 2016
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CROSSREFS
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KEYWORD
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nonn,more
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AUTHOR
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STATUS
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approved
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