Supported by the National Natural Science Foundation of China (10871158, 70871098);the Natural Science Basic Research Plan in Shaanxi Province of China (SJ08A01, 2007A09) and SRF for ROCS, SEM
A graph G is called integral if all the eigenvalues of the adjacency matrix A(G) of G are integers. In this paper, the graphs G4(a, b) and Gs(a, b) with 2a + 6b vertices are defined. We give their characteristi...