On the exponential Diophantine equation $(18m^2+1)^x+(7m^2-1)^y=(5m)^z$

Authors: MURAT ALAN

Abstract: Let $m$ be a positive integer. We show that the exponential Diophantine equation $ (18m^2+1)^x+(7m^2-1)^y=(5m)^z $ has only the positive integer solution $(x,y,z)=(1,1,2)$ except for $m \equiv 23,47,63, 87 \pmod {120}$. For $m\not\equiv 0 \pmod5$ we use some elementary methods and linear forms in two logarithms. For $m \equiv 0 \pmod 5$ we apply a result for linear forms in $p$-adic logarithms.

Keywords: Exponential Diophantine equations, linear forms in the logarithms

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