{ "id": "1905.11322", "version": "v1", "published": "2019-05-27T16:15:42.000Z", "updated": "2019-05-27T16:15:42.000Z", "title": "On the $x-$coordinates of Pell equations which are sums of two Padovan numbers", "authors": [ "Mahadi Ddamulira" ], "comment": "30 pages", "categories": [ "math.NT" ], "abstract": "Let $ \\{P_{n}\\}_{n\\geq 0} $ be the sequence of Padovan numbers defined by $ P_0=0 $, $ P_1 = P_2=1$ and $ P_{n+3}= P_{n+1} +P_n$ for all $ n\\geq 0 $. In this paper, we find all positive square-free integers $ d $ such that the Pell equations $ x^2-dy^2 = \\pm 1 $, $ X^2-dY^2=\\pm 4 $ have at least two positive integer solutions $ (x,y) $ and $(x^{\\prime}, y^{\\prime})$, $ (X,Y) $ and $(X^{\\prime}, Y^{\\prime})$, respectively, such that each of $ x, ~x^{\\prime}, ~X, ~X^{\\prime} $ is a sum of two Padovan numbers.", "revisions": [ { "version": "v1", "updated": "2019-05-27T16:15:42.000Z" } ], "analyses": { "subjects": [ "11A25", "11B39", "11J86" ], "keywords": [ "padovan numbers", "pell equations", "coordinates", "positive square-free integers" ], "note": { "typesetting": "TeX", "pages": 30, "language": "en", "license": "arXiv", "status": "editable" } } }