Sequences And Series

Given that x, y, and z are three consecutive positive integers and x \(-\) z + 2 = 0, what is the value of \({1 \over 2}{\log _e}x + {1 \over 2}{\log _e}z + {1 \over {2xz + 1}} + {1 \over 3}{\left( {{1 \over {2xz + 1}}} \right)^3} + ...\)?