BIB(9,18t,8t,4,3t) designs with repeated blocks
The set of distinct blocks of a BIB(\(\nu\),b,r,k,\(\lambda)\) design is referred to as the support of a design. Via a computer program based on the methods of tradeoff and composition of designs, a table of 105 BIB designs based on \(\nu =9\), \(k=4\) with support sizes \(18\leq b^*\leq \left( \begin{matrix} 9\\ 4\end{matrix} \right)=126\) except for \(b^*=19,20,21,23\) have been constructed. BIB designs with \(\nu =9\), \(k=4\) and \(b^*<18\) are shown to be non-existent.
scientific article; zbMATH DE number 4024561