Abstract
We investigate the solvability of the Diophantine equation in the title, where \(d>1\) is a square-free integer, p, q are distinct odd primes and x, y, a, b are unknown positive integers with \(\gcd (x,y)=1\). We describe all the integer solutions of this equation, and then use the main finding to deduce some results concerning the integers solutions of some of its variants. The methods adopted here are elementary in nature and are primarily based on the existence of the primitive divisors of certain Lehmer numbers.
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References
Arif, S.A., Al-Ali, A.: On the Diophantine equation \(ax^2 + b^m = 4y^n\). Acta Arith. 103, 343–346 (2002)
Bhatter, S., Hoque, A., Sharma, R.: On the solutions of a Lebesgue-Nagell type equation. Acta Math. Hungar. 158(1), 17–26 (2019)
Bilu, Y., Hanrot, G., Voutier, P.M.: Existence of primitive divisors of Lucas and Lehmer numbers (with an appendix by M. Mignotte). J. Reine Angew. Math. 539, 75–122 (2001)
Bilu, Y.: On Le’s and Bugeaud’s papers about the equation \(ax^2 + b^{2m-1} = 4c^p\). Monatsh. Math. 137, 1–3 (2002)
Bugeaud, Y.: On some exponential Diophantine equations. Monatsh. Math. 132, 93–97 (2001)
Bugeaud, Y., Shorey, T.N.: On the number of solutions of the generalized Ramanujan-Nagell equation. J. Reine Angew. Math. 539, 55–74 (2001)
Chakraborty, K., Hoque, A., Sharma, R.: Complete solutions of certain Lebesgue-Ramanujan-Nagell equations. Publ. Math. Debrecen 97(3–4), 339–352 (2020)
Chakraborty, K., Hoque, A., Srinivas, K.: On the Diophantine equation \(cx^2+p^{2m}=4y^n\), Results Math. 76 (2021), no. 2, 12pp, article no. 57
Cohn, J.H.E.: Square Fibonacci numbers, etc.,. Fibonacci Quart. 2(2), 109–113 (1964)
Dabrowski, A., Günhan, N., Soydan, G.: On a class of Lebesgue-Ljunggren-Nagell type equations. J. Number Theory 215, 149–159 (2020)
Hoque, A.: On a class of Lebesgue-Ramanujan-Nagell equations, submitted for publication, ArXiv: 2005.05214
Keskin, R., Karaatli, O.: Generalized Fibonacci and Lucas numbers of the form \(5x^2\). Int. J. Number Theory 11(3), 931–944 (2015)
Le, M.: On the Diophantine equation \(x^2 + D = 4p^n\). J. Number Theory 41(1), 87–97 (1992)
Le, M.: On the Diophantine equation \(D_1x^2+D_2=4y^n\). Monatsh. Math. 120, 121–125 (1995)
Le, M., Soydan, G.: A brief survey on the generalized Lebesgue-Ramanujan-Nagell equation. Surv. Math. Appl. 115, 473–523 (2020)
Ljunggren, W.: New theorems concerning the Diophantine equation \(x^2 + D = 4y^n\). Acta Arith. 21, 183–191 (1972)
Luca, F., Tengely, Sz., Togbé, A.: On the Diophantine equation \(x^2 +C = 4y^n\). Ann. Sci. Math. Québec 33(2), 171–184 (2009)
Mignotte, M.: On the Diophantine equation \(D_1x^2+D_2^m=4y^n\). Portugal Math. 54, 457–460 (1997)
Sharma, R.: On Lebesgue-Ramanujan-Nagell type equations. In: Chakraborty, K., Hoque, A., Pandey, P. (eds.) Class Groups of Number Fields and Related Topics, pp. 147–161. Springer, Singapore (2020)
Voutier, P.M.: Primitive divisors of Lucas and Lehmer sequences. Math. Comp. 64, 869–888 (1995)
Yuan, P.Z.: On the Diophantine equation \(ax^2 + by^2 = ck^n\). Indag. Math. (N. S.) 16(2), 301–320 (2005)
Acknowledgements
This work is supported by the grants SERB MATRICS Project No. MTR/2017/001006 and SERB-NPDF (PDF/2017/001958), Govt. of India. The authors are grateful to the anonymous referee for careful reading and valuable comments which have helped to improve this paper.
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Chakraborty, K., Hoque, A. On the Diophantine Equation \(dx^2+p^{2a}q^{2b}=4y^p\). Results Math 77, 18 (2022). https://doi.org/10.1007/s00025-021-01560-w
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DOI: https://doi.org/10.1007/s00025-021-01560-w