摘要
本文给出了r为偶数,直径为4的树S(r,mi)为整树的一个充分条件。由此得到了r为偶数直径为4的整树S(r,mi)的一些新类,给出了它们的谱。同时表明这类整树有无穷多个。
A sufficient condition that trees S(r,m i) of diameter 4 are integral trees when r is even number is given. Some new classes of the integral trees S(r,m i) whose diameters are 4 and r is even number are obtained from this, and their spectra are presented. The results indicated that there are infinitely many such integral trees. Thus answered a question in .
出处
《河北大学学报(自然科学版)》
CAS
1997年第1期12-16,共5页
Journal of Hebei University(Natural Science Edition)
基金
青海省教委资助
关键词
直径
整树
特征多项式
树
图论
Diameter Integral tree Even number Spectrum