Abstract
Let a, b, c, r be positive integers such that a 2 + b 2 = c r, min(a, b, c, r) > 1, gcd(a, b) = 1, a is even and r is odd. In this paper we prove that if b ≡ 3 (mod 4) and either b or c is an odd prime power, then the equation x 2 + b y = c z has only the positive integer solution (x, y, z) = (a, 2, r) with min(y, z) > 1.
Similar content being viewed by others
References
Y. Bilu, G. Hanrot and P. Voutier (with an appendix by M. Mignotte): Existence of primitive divisors of Lucas and Lehmer numbers. J. Reine Angew. Math. 539 (2001), 75–122.
Y. Bugeaud: On some exponential diophantine equations. Monatsh. Math. 132 (2001), 93–97.
Z.-F. Cao and X.-L. Dong: The diophantine equation a 2+ b y = c z. Proc. Japan Acad. 77A (2001), 1–4.
Z.-F. Cao, X.-L. Dong and Z. Li: A new conjecture concerning the diophantine equation x 2 + b y = c z. Proc. Japan Acad. 78A (2002), 199–202.
L. Jeśmanowicz: Several remarks on Pythagorean number. Wiadom. Mat. 1 (1955/1956), 196–202. (In Polish.)
C. Ko: On the diophantine equation x 2 = y n + 1, x y ≠ 0. Sci.Sin. 14 (1964), 457–460.
M.-H. Le: A note on Jeśmanowicz’ conjecture. Colloq. Math. 64 (1995), 47–51.
L. J. Mordell: Diophantine Equations. Academic Press, London, 1969.
T. Nagell: Sur I’impossibilitè de quelques equation á deux indèterminèes. Norsk Matem. Forenings Skrifter 13 (1921), 65–82.
N. Terai: The diophantine equation x 2 + q m = p n. Acta Arith. 63 (1993), 351–358.
P. Voutier: Primitive divisors of Lucas and Lehmer sequences. Math. Comp. 64 (1995), 869–888.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Le, M. A note on the diophantine equation x 2 + b y = c z . Czech Math J 56, 1109–1116 (2006). https://doi.org/10.1007/s10587-006-0082-9
Received:
Issue Date:
DOI: https://doi.org/10.1007/s10587-006-0082-9