Fundamental solutions of a Pell equation
Problèmes ouverts — A. Dujella · 2026 · ★★★★★
Statement
Problem 4.2 (Dujella, 2026). Is there any positive integer $k$, $k \neq 33539$, such that the Pellian equation \[ x^2-(k^2-1)y^2=2-k^2 \] has more than four fundamental solutions?
Remark. For $k=33539$ there are six fundamental solutions: $(\pm 1,1)$, $(\pm 669941,20)$, $(\pm 4326401,129)$.
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Source & credits
Origin : Andrej Dujella, Open problems on Diophantine m-tuples and elliptic curves (26 juillet 2026), Problème 4.2
Reproduit à des fins pédagogiques non commerciales, avec attribution à l'auteur. Problème de recherche ouvert : aucune solution connue à ce jour.
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