Unitary Perfect Number

Author

Eric W. Weisstein
February 1, 2004

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

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

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

Enumeration

Select[Range[10^5],2#==UnitaryDivisorSigma[1,#]&]//Timing