  The Nagumo lattice differential equation admits stationary solutions with
arbitrary spatial period for sufficiently small diffusion rate. The
continuation from the stationary solutions of the decoupled system (a system of
isolated nodes) is used to determine their types; the solutions are labelled by
words from a three-letter alphabet. Each stationary solution type can be
assigned a parameter region in which the solution can be uniquely identified.
Numerous symmetries present in the equation cause some of the regions to have
identical or similar shape. With the help of combinatorial enumeration, we
derive formulas determining the number of qualitatively different existence
regions. We also discuss possible extensions to other systems with more general
nonlinear terms and/or spatial structure.
