The authors establish the oscillation of all nontrivial solutions of the second order linear difference equation
is bounded below by a certain expression involving the iterated logarithm functions. The presented oscillation result (Theorem 2.1) is a completion of the corresponding nonoscillation result for this difference equation obtained earlier by the same authors [J. Difference Equ. Appl. 16, No. 9, 1047–1056 (2010; Zbl 1207.39014
)], in which the coefficient
is bounded above by an expression of the same type as described above.