UKRAINIAN MATHEMATICAL JOURNAL, cilt.68, sa.2, ss.193-202, 2016 (SCI-Expanded)
We study the Lehmer sequences modulo m. Moreover, we define the Lehmer orbit and the basic Lehmer orbit of a 2-generator group G for a generating pair (x, y) a G and examine the lengths of the periods of these orbits. Furthermore, we obtain the Lehmer lengths and the basic Lehmer lengths of the Fox groups G (1,t) for t aeyen 3.