Quasiperfect Number

Author

Eric W. Weisstein
March 31, 2004

This notebook downloaded from http://mathworld.wolfram.com/notebooks/NumberTheory/QuasiperfectNumber.nb.

For more information, see Eric's MathWorld entry http://mathworld.wolfram.com/QuasiperfectNumber.html.

©2005 Wolfram Research, Inc. except for portions noted otherwise

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Position[Table[DivisorSigma[1,n]-(2n+1),{n,10^6}],0,{1}]//Timing

Position[Table[DivisorSigma[1,n]-(2n+1),{n,10^7}],0,{1}]//Timing

Position[Table[DivisorSigma[1,n]-(2n+1),{n,10^8}],0,{1}]//Timing