Aspiring Number

Author

Eric W. Weisstein
March 14, 2009

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

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

©2009 Wolfram Research, Inc. except for portions noted otherwise

Enumeration

l=DeleteCases[With[{m=200},Table[NestWhileList[DivisorSigma[1,#]-#&,n,Last[{##}]=!=0&&Unequal[##]&,All,m],{n,200}]],{__,0}]

Union[Flatten[Drop[#,-2]&/@l]]