摘要
确定Ｒａｍｓｅｙ数是图论和组合数学中的著名难题，并且当被研究的Ｒａｍｓｅｙ数较大时，仅仅给出一个较好的下界也是相当困难的。根据群论和数论研究了素数阶循环图存在４阶团的充要条件，应用这个方法，借助计算机的计算。
It is well known that to determine the Ramsey number is a big problem in the fields of the graph theory and combinational mathematics,so is a difficult work in getting a good lower bound,especially when the Ramsey number is getting bigger and bigger.The sufficient and necessary condition for the existing of the cycle graph of prime numbers in 4-order clique is discussed based on the group theory and the number theory. A new lower bound of the Ramsey number R 7(4) given.
出处
《桂林电子工业学院学报》
1997年第2期49-52,共4页
Journal of Guilin Institute of Electronic Technology
关键词
RAMSEY数
下界
循环图
The Ramsey number,Lower bound,Cycle graph
