至多有2个等长圈的简单图的最大边数

The Maximum Number of Edges in a Simple Graph in Which at Most Two Cycles Have the Same Length

分f*（n，2）表示具有n个顶点的至多有2个等长国的简单图的最大边数．证明了当n≥15时，f*（n，2）≥n＋2Zk－4＋［」，其中k＝［（16＋／42）．

Let f (n, 2) be the maximum number of edges on a simple graph on n vertices inwhich at most two cycles have the same length. We prove that f* (n,2) ≥n + 2k - 4 +[ ], for each integer n ≥ 15, where k = [].