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arXiv · 2201.06939

On Power Values of Sum of Divisors function in Arithmetic Progressions

Sai Teja Somu·Vidyanshu Mishra
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Abstract

Let $a\geq 1, b\geq 0$ and $k\geq 2$ be any given integers. It has been proven that there exist infinitely many natural numbers $m$ such that sum of divisors of $m$ is a perfect $k$th power. We try to generalize this result when the values of $m$ belong to any given infinite arithmetic progression $an+b$. We prove if $a$ is relatively prime to $b$ and order of $b$ modulo $a$ is relatively prime to $k$ then there exist infinitely many natural numbers $n$ such that sum of divisors of $an+b$ is a perfect $k$th power. We also prove that, in general, either sum of divisors of $an+b$ is not a perfect $k$th power for any natural number $n$ or sum of divisors of $an+b$ is a perfect $k$th power for infinitely many natural numbers $n$.

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Sai Teja Somu, Vidyanshu Mishra. 2022-01-03. On Power Values of Sum of Divisors function in Arithmetic Progressions. https://arxiv.org/abs/2201.06939

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