一个六阶3-连通图与路P_n的笛卡尔积的交叉数

The Crossing Number of Cartesian Product of a 3-connected Graph with Six Vertices and a Path

C(6,2)表示由圈C6增加边vivi+2(i=1,…,6,i+2(m od6))所得的图,把边vivi+2叫做C(6,2)的弦,B表示C(6,2)除去一条弦所得到的图,我们确定了B与Pn笛卡尔积的交叉数为5n-1.

C（6,2） is a graph obtained by adding edges vivi＋z（i=1,…,6,1＋2（mod6））,B is a graph obtained from C（6,2）by removing an edge vivi＋2. We have proved that the crossing number of the Cartesian product of B with path Pn is 5n-1.