On certain regular graphs of girth 5
M O'Keefe, Pak‐Ken Wong · International Journal of Mathematics and Mathematical Sciences · 1984
Let f(v, 5) be the number of vertices of a (v, 5)‐cage (v ≥ 3). We give an upper bound for f(v, 5) which is considerably better than the previously known upper bounds. In particular, when v = 7, it coincides with the well‐known Hoffman‐ Singleton graph.