The Markov numbers are the union of the solutions to this equation and are related to Lagrange numbers.
Markov Equation
See also
Markov Number, Lagrange NumberExplore with Wolfram|Alpha
References
Cusick, T. W. and Flahive, M. E. The Markov and Lagrange Spectra. Providence, RI: Amer. Math. Soc., 1989.Referenced on Wolfram|Alpha
Markov EquationCite this as:
Weisstein, Eric W. "Markov Equation." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/MarkovEquation.html