Quasi-symmetric designs with the difference of block intersection numbers two
This paper considers 2-designs with two intersection numbers, which is called quasi-symmetric designs. It is shown that if \(D(v, b, r, k, \lambda)\) is a quasi-symmetric design with intersection numbers \(x\) and \(x+2\), then either \(\lambda = x+1\) or \(x+2\) with exceptions listed in a Table, or a complement design of these designs.
scientific article; zbMATH DE number 5864183