Some remarks on Stolt's theorems for Pellian equations (Q1212029)

The author indicates that one of the theorems of \textit{B. Stolt} [Ark. Mat. 3, 117--132 (1955; Zbl 0064.04004)] is not quite correct in its entirety; namely, the theorem that states that the number of classes of solutions of the Diophantine equation \(u^2-Dv^2=4N\) \((N\) square-free) is a power of two. A counterexample in the form of \(u^2-79v^2=4(1365)\) is given. The author also proves two theorems on the evaluation of the number of classes of solutions of Diophantine equations of similar type.