Perfect powers in products of terms of elliptic divisibility sequences

Abstract

Diophantine problems involving recurrence sequences have a long history and is an actively studied topic within number theory. In this paper, we connect to the field by considering the equation \begin{align*} B_mB_{m+d}\dots B_{m+(k-1)d}=y^\ell \end{align*} in positive integers $m,d,k,y$ with $\gcd (m,d)=1$ and $k\ge 2$, where $\ell \ge 2$ is a fixed integer and $B=(B_n{)}_{n=1}^{\infty }$ is an elliptic divisibility sequence, an important class of non-linear recurrences. We prove that the above equation admits only finitely many solutions. In fact, we present an algorithm to find all possible solutions, provided that the set of $\ell$-th powers in $B$ is given. (Note that this set is known to be finite.) We illustrate our method by an example.

To appear in Bulletin of Australian Math Society