 Möbius ladder

In graph theory, the Möbius ladder "M""n" is a cubic circulant graph with an even number "n" of vertices, formed from an "n"-cycle by adding edges (called "rungs") connecting opposite pairs of vertices in the cycle.It is so-named because (with the exception of "M"6 = "K"3,3) "M""n" has exactly "n"/2 4-cycles which link together by their shared edges to form a topological Möbius strip.