On the x-coordinates of Pell equations which are Fibonacci numbers
DOI:
https://doi.org/10.7146/math.scand.a-97271Abstract
For an integer d>2 which is not a square, we show that there is at most one value of the positive integer x participating in the Pell equation x2−dy2=±1 which is a Fibonacci number.
References
Bugeaud, Y., Mignotte, M., and Siksek, S., Classical and modular approaches to exponential Diophantine equations. I. Fibonacci and Lucas perfect powers, Ann. of Math. (2) 163 (2006), no. 3, 969–1018. https://doi.org/10.4007/annals.2006.163.969
Carmichael, R. D., On the numerical factors of the arithmetic forms alphanpmbetan, Ann. of Math. (2) 15 (1913/14), no. 1-4, 30–70. https://doi.org/10.2307/1967797
Cohn, J. H. E., On square Fibonacci numbers, J. London Math. Soc. 39 (1964), 537–540. https://doi.org/10.1112/jlms/s1-39.1.537
Cohn, J. H. E., The Diophantine equation x4−Dy2=1, Quart. J. Math. Oxford Ser. (2) 26 (1975), no. 1, 279–281. https://doi.org/10.1093/qmath/26.1.279
Cohn, J. H. E., The Diophantine equation x4−Dy2=1. II, Acta Arith. 78 (1997), no. 4, 401–403. https://doi.org/10.4064/aa-78-4-401-403
Dujella, A. and Pethő, A., A generalization of a theorem of Baker and Davenport, Quart. J. Math. Oxford Ser. (2) 49 (1998), no. 3, 291–306. https://doi.org/10.1093/qjmath/49.195.291
Kalman, D. and Mena, R., The Fibonacci numbers—exposed, Math. Mag. 76 (2003), no. 3, 167–181. https://doi.org/10.2307/3219318
Ljunggren, W., Über die unbestimmte Gleichung Ax2−By4=C, Arch. Math. Naturvid. 41 (1938), no. 10, 18.
Ljunggren, W., Über die Gleichung x4−Dy2=1, Arch. Math. Naturvid. 45 (1942), no. 5, 61–70.
Ljunggren, W., On the Diophantine equation x2+4=Ay4, Norske Vid. Selsk. Forh., Trondheim 24 (1951), 82–84.
Ljunggren, W., Collected papers of Wilhelm Ljunggren. Vol. 1, 2, Queen's Papers in Pure and Applied Mathematics, vol. 115, Queen's University, Kingston, ON, 2003.
Matveev, E. M., An explicit lower bound for a homogeneous rational linear form in logarithms of algebraic numbers. II, Izv. Ross. Akad. Nauk Ser. Mat. 64 (2000), no. 6, 125–180. https://doi.org/10.1070/IM2000v064n06ABEH000314
McDaniel, W. L., The g.c.d. in Lucas sequences and Lehmer number sequences, Fibonacci Quart. 29 (1991), no. 1, 24–29.
Ming, L., On triangular Fibonacci numbers, Fibonacci Quart. 27 (1989), no. 2, 98–108.
Posamentier, A. S. and Lehmann, I., The (fabulous) Fibonacci numbers, Prometheus Books, Amherst, NY, 2007.
Rollett, A. P. and Wyler, O., Advanced Problems and Solutions: Solutions: 5080, Amer. Math. Monthly 71 (1964), no. 2, 220–222.