{"title":"On the x-coordinates of Pell equations that are products of two Pell numbers","authors":"Mahadi Ddamulira, Florian Luca","doi":"10.1515/ms-2024-0004","DOIUrl":null,"url":null,"abstract":"Let (<jats:italic>P<jats:sub>m</jats:sub> </jats:italic>)<jats:sub> <jats:italic>m</jats:italic>≥0</jats:sub> be the sequence of Pell numbers given by <jats:italic>P</jats:italic> <jats:sub>0</jats:sub> = 0, <jats:italic>P</jats:italic> <jats:sub>1</jats:sub> = 1, and <jats:italic>P</jats:italic> <jats:sub> <jats:italic>m</jats:italic>+2</jats:sub> = 2<jats:italic>P</jats:italic> <jats:sub> <jats:italic>m</jats:italic>+1</jats:sub> + <jats:italic>P<jats:sub>m</jats:sub> </jats:italic> for all <jats:italic>m</jats:italic> ≥ 0. In this paper, for an integer <jats:italic>d</jats:italic> ≥ 2 which is square free, we show that there is at most one value of the positive integer <jats:italic>x</jats:italic> participating in the Pell equation <jats:italic>x</jats:italic> <jats:sup>2</jats:sup> − <jats:italic>dy</jats:italic> <jats:sup>2</jats:sup> = ± 1, which is a product of two Pell numbers.","PeriodicalId":0,"journal":{"name":"","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"","FirstCategoryId":"100","ListUrlMain":"https://doi.org/10.1515/ms-2024-0004","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
Let (Pm)m≥0 be the sequence of Pell numbers given by P0 = 0, P1 = 1, and Pm+2 = 2Pm+1 + Pm for all m ≥ 0. In this paper, for an integer d ≥ 2 which is square free, we show that there is at most one value of the positive integer x participating in the Pell equation x2 − dy2 = ± 1, which is a product of two Pell numbers.