Grannell, Mike; Griggs, Terry; Stanton, R. G. and Whitehead, C. A.
On the covering number .
Utilitas Mathematica, 68, pp. 131–143.
The minimum number of blocks having maximum size precisely four that are required to cover, exactly times, all pairs of elements from a set of cardinality is denoted by . The values of are known apart from the cases and . We prove that , thereby reducing this outstanding case to just two possible values, namely 32 and 33.
Actions (login may be required)