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2024/104/3-4 (8) — DOI: 10.5486/PMD.2024.9723 — pp. 423-441

Padovan squares which are again Padovan

Authors: Eric Fernando Bravo Orcid.org link for Eric Fernando Bravo and Florian Luca Orcid.org link for Florian Luca

Abstract:

The integer sequence defined by $P_{n+1}=P_{n-1}+P_{n-2}$ with initial values $P_{0}=P_{1}=P_{2}=1$ is known as the Padovan sequence $(P_n)_{n\in \mathbb{Z}}$. In this note, we solve the Diophantine equations $P_{-n}=\pm P_{m}^{2}$, $P_{n}=P_{-m}^{2}$, and $P_{-n}=\pm P_{-m}^{2}$ in positive integers $n,m$.

Keywords: Padovan number, linear form in logarithms, Baker's method

Mathematics Subject Classification: 11B39, 11J86