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2026/109/3-4 (9) — DOI: 10.5486/PMD.2026.10488 — pp. 451-472

On the Diophantine equation $\prod_{i=1}^{m}(a_{i}^{k}-1)=y^{n}$

Authors: Shichun Yang Orcid.org link for Shichun Yang and Alain Togbé Orcid.org link for Alain Togbé

Abstract:

In this paper, we consider the Diophantine equation $\prod_{i=1}^{m}(a_{i}^{k}-1)=y^{n}$, where $m\geq3$, $a_{1},a_{2},\dots,a_{m}$ are fixed integers which are pairwise coprime. We have proved that the equation has only finitely many solutions $(k,y,n)$ with $n>1$. We also study some special cases of equation when $m=3$ and $m=4$.

Keywords: exponential Diophantine equation, the finiteness of the solution, lifting the exponent lemma, congruences

Mathematics Subject Classification: 11D41, 11D61