>Smallest odd number A such that sigma(x)=A has n solutions. > >So: sigma(16)=31 and sigma(25)=31. > I think the sequence begins 1, 31, 347529, 10773399 The 3 numbers with sigma(k)=347529 are 164836, 203522, 239121 The 4 numbers with sigma(k)=10773399 are 3825936, 4120900, 5088050, 5978025 Tony