【摘要】 给定图G和H,如果图G不包含图H作为子图,则称图G是禁用H的.用ex_ICP（n,F,H）表示在所有禁用H且顶点数为n的IC-可平面图中,含与F同构的子图的最大个数.本文证明了对任意的k≥5,当n充分大时,有ex_ICP（n,C_k,C₄）=Θ（■）.更多还原

【Abstract】 Let G and H be two graphs.A graph G is H-free if G contains no H as a subgraph.Let ex_ICP（n,F,H） denote the maximum number of copies of F in an H-free ICplanar graph of order n.In this paper,we prove that ex_ICP（n,C_k,C₄）=Θ（■） for all k≥5and sufficiently large n.更多还原