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A063870
Numbers n such that sigma(n) - usigma(n) = 3n/2.
1
480, 2688, 2095104, 16854816, 41055200, 1839272960, 5905219584, 204004720640
OFFSET
1,1
PROG
(PARI) u(n) = sumdiv(n, d, if(gcd(d, n/d)==1, d)); for(n=1, 10000, if(sigma(n)-u(n)==3*n/2, print(n)))
CROSSREFS
KEYWORD
nonn
AUTHOR
Jason Earls, Aug 27 2001
EXTENSIONS
More terms from Dean Hickerson, Sep 25 2001
There are no others less than 1.5*10^13, but here's a larger one: 948990933336933380096. - Dean Hickerson, Sep 25 2001
STATUS
approved