一个5阶图与点、路、圈联图的交叉数

The crossing numbers of the join of a 5-vertex graph with vertex,path and cycle

分别讨论了5阶图G16与nK1,Pn,Cn联图的交叉数,得到cr(G16+nK1)=Z(5,n)+n+n/2,n≥1;cr(G16+Pn)=Z(5,n)+n+n/2+1,n≥2;cr(G16+Cn)=Z(5,n)+n+n/2+3,n≥3,其中nK1是n个孤立点构成的图,Pn,Cn分别是含n个点的路和圈.

This paper discusses the crossing numbers of the join of nK1, Pn and Cn with a 5-vertex graph G16, i. e., cr（G16＋nK1）=Z（5,n）＋n＋L n/2 ], n≥1, cr（G16＋Pn）=Z（5,n）＋n＋L n/2 ]＋1,n≥2 and cr（G16 ＋Cn） = Z（5, n） ＋n＋[ n/2 ]＋ 3, n≥3, where nK1 denotes n isolated vertices, while P. and C. are the path and cycle on n vertices, respectively.