Forty-three balanced incomplete block designs
A balanced incomplete block design (BIBD) with parameters \((v,b,r,k,\lambda)\) consists of a \(v\)-set \(S\) plus \(b\) \(k\)-element subsets of \(S\) called blocks satisfying the following conditions: (1.1) Every element of \(S\) appears in \(r\) blocks. (1.2) Any two distinct elements of \(S\) appear together in \(\lambda\) blocks. A resolvable BIBD is one whose blocks can be partitioned into \(r\) mutually disjoint resolution classes of size \(b/r\). Almost all of the forty-three new BIBDs presented in this paper are obtained by direct constructions via difference methods; many are addenda to the list compiled by \textit{R. Mathon} and \textit{A. Rosa} [Ars Comb. 30, 65-96 (1990; Zbl 0734.05012)].
scientific article; zbMATH DE number 554400