Nonaliquots and Robbins numbers

Abstract

Let $\varphi(\cdot)$ and $\sigma(\cdot)$ denote the Euler function and the sum of divisors function, respectively. We give a lower bound for the number of $m\le x$ for which the equation $m=\sigma(n)-n$ has no solution. We also show that the set of positi

Locations

• Colloquium Mathematicum - View - PDF