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2025/107/3-4 (12) — DOI: 10.5486/PMD.2025.10306 — pp. 499-515

On $k$-generalized Fibonacci numbers which are perfect powers of Lucas numbers

Authors: Fatıh Erduvan Orcid.org link for Fatıh Erduvan, Florian Luca Orcid.org link for  Florian Luca, Merve Güney Duman Orcid.org link for  Merve Güney Duman and Faith Shadow Zottor Orcid.org link for Faith Shadow Zottor

Abstract:

Let $(F_{n}^{(k)})$ and $(L_{n})$ be the $k$-generalized Fibonacci and Lucas sequences, respectively. In this paper, we look at $k$-generalized Fibonacci numbers which are perfect powers of exponent larger than $1$ of Lucas numbers. That is, we deal with the Diophantine equation \begin{equation*} F_{n}^{(k)}=L_{m}^{a} \end{equation*} in non-negative integers $k$, $n$, $m$, $a$, with $k\geq 3$, $m\geq 4$ and $a\geq 2$. We show that this equation has no solution under these conditions. The proof depends on lower bounds for linear forms in logarithms and some tools from Diophantine approximation.

Keywords: $k$-generalized Fibonacci numbers, Lucas numbers, exponential Diophantine equations, Baker's method

Mathematics Subject Classification: 11B39, 11B83, 11D61, 11J86