Title: Integrable 7-point discrete equations and evolution lattice equations of order 2,
Abstract: We consider differential-difference equations that determine the continuous
symmetries of discrete equations on the triangular lattice. It is shown that a
certain combination of continuous flows can be represented as a scalar
evolution lattice equation of order 2. The general scheme is illustrated by a
number of examples, including an analog of the elliptic Yamilov lattice
equation.