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Indexed by:期刊论文

Date of Publication:2009-11-01

Journal:UTILITAS MATHEMATICA

Included Journals:SCIE、Scopus

Volume:80

Page Number:115-130

ISSN No.:0315-3681

Key Words:extremal graph; forbidden subgraph

Abstract:Given a set of graphs Psi = {G(1), G(2), ... , G(k)}, let ex(n; Psi) denote the greatest size of a graph with order n that contains no subgraph isomorphic to any G(i), 1 <= i <= k. Clapham and Yang Yuansheng investigated the values of ex(n, Psi) for Psi = {C(4)}( Journal of Graph Theory, 13 (1989), 29-47 and Utilitas Mathematica, 41 (1992), 204-210) and ex(n, Psi) for Psi = {C(3), C(4), C(5)}(Utilitas Mathematica, 66 (2004), 249-265). Garnick investigated them for Psi = {C(3), C(4)} (Journal of Graph Theory, 17 (1993), 633-645). This paper investigates the values of ex (n, Psi) for Psi = {C(4), C(5)}, n <= 21.