Unicyclic graphs derived from square-cell animals. (English) Zbl 0847.05081
Summary: This is a sequel to the theorem of Exoo and Harary which characterized the trees derived from square-cell animals by equating them with caterpillars. Here we characterize the unicyclic graphs derived from square-cell animals, showing that the unique cycle is \(C_4\) and that the trees rooted at the nodes of the \(C_4\) are caterpillars.