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A063875
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Numbers k such that sigma(k) - usigma(k) > 3k.
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1
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831600, 1058400, 1587600, 1663200, 1814400, 1940400, 1965600, 2116800, 2328480, 2494800, 2570400, 2646000, 2721600, 2872800, 2910600, 2948400, 3024000, 3175200, 3326400, 3528000, 3603600, 3628800, 3704400, 3880800, 3931200
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OFFSET
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1,1
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LINKS
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PROG
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(PARI) u(n) = sumdiv(n, d, if(gcd(d, n/d)==1, d));
for(n=1, 10^9, if(sigma(n)-u(n)>3*n, print(n)))
(PARI) u(n) = sumdiv(n, d, if(gcd(d, n/d)==1, d))
{ n=0; for (m=1, 10^9, if(sigma(m) - u(m) > 3*m, write("b063875.txt", n++, " ", m); if (n==1000, break)) ) } \\ Harry J. Smith, Sep 01 2009
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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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