Cycle graph

In graph theory, a cycle graph or circular graph is a graph that consists of a single cycle, or in other words, some number of vertices (at least 3, if the graph is simple) connected in a closed chain. The cycle graph with n vertices is called C_n. The number of vertices in C_n equals the number of edges, and every vertex has degree 2; that is, every vertex has exactly two edges incident with it.

Cycle
Girth	n
Automorphisms	2n (Dn)
Chromatic number	3 if n is odd 2 otherwise
Chromatic index	3 if n is odd 2 otherwise
Spectrum	${\displaystyle \left\{2\cos \left({\frac {2k\pi }{n}}\right);k=1,\cdots ,n\right\}}$
Properties	2-regular Vertex-transitive Edge-transitive Unit distance Hamiltonian Eulerian
Notation	Cn
Table of graphs and parameters