Invariants for difference equations and systems of difference equations of rational form
The author consideres the system of difference equations \[ x_{n+1} = \frac{a_n y_n + A}{x_{n-1}}, \qquad y_{n+1} = \frac{b_n x_n + A}{y_{n-1}}, n = 0, 1,\dots\tag{1} \] where the coefficients \(\{a_n\}\) and \(\{b_n\}\) are periodic sequences of positive numbers of period 2 and \(A\) is a positive constant. Some invariants for system (1) are presented. In the second part of the article, some invariants for difference equations of higher than second order are found.
systems of difference equations of rational form
scientific article; zbMATH DE number 1115528