The Pell equation, by Edward Everett Whitford.

THE PELL EQUATION

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The author makes application to the equation
X2 + y2 = z2
when two of the three unknown are consecutive integers.
E. B. ESCOTT, T. HAYASHI, "The equation
2 - Dy2 = 4zn."
L'Intermediare des mathematiciens, vol. XV, p. 153, vol.
XVII, p. 2, 137, 229, 253, Paris, 1908, 1910.
R. BRICARD, "Le produit de huit nombres entiers consecutifs ne peut etre un carre parfait," L'Intermediare
des mathematiciens, vol. XVII, p. 139, Paris, 1910.
The theory of the Pell equation is used in the demonstration that the product of eight consecutive integers can
not be a perfect square.
L. W. REID, "The elements of the theory of algebraic
numbers," p. 423, New York, 1910.
Pell's equation is discussed in connection with the determination of the units of a real quadratic "realm."
D. N. RANUCCI, "Risoluzione dell' equazione
xn - Ayn = = 1
con una nuova dimostrazione dell' teorema di Fermat,"
Rome, 1911.

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