2021/01/04 by LE Mao-hua, Le, Maohua, Gökhan Soydan +1
Mathematics · #Algebraic Geometry and Number Theory #Analytic Number Theory Research #Mathematical Dynamics and Fractals
paper · pdf · doi:10.48550/arxiv.2101.01136
In this paper, using a deep result on the existence of primitive divisors of Lehmer numbers due to Y. Bilu, G. Hanrot and P. M. Voutier, we first give an explicit formula for all positive integer solutions of the Diophantine equation (x-d)2+x2+(x+d)2=yn (*) when n is an odd prime and d=pr, p>3 a prime. So this improves the results on the papers of A. Koutsianas and V. Patel \citeKP and A. Koutsianas \citeKou. Secondly, under the assumption of our first result, we prove that (*) has at most one solution (x,y). Next, for a general d, we prove the following two results: (i) if every odd prime divisor q of d satisfies q\not≡ ± 1 \pmod2n, then (*) has only the solution (x,y,d,n)=(21,11,2,3). (ii) if n>228000 and d>8√(2), then all solutions (x,y) of (*) satisfy yn<23/2d3.