On -fold coverings with maximum block size four for

Grannell, M. J.; Griggs, T. S. and Stanton, RG (2004). On -fold coverings with maximum block size four for . Utilitas Mathematica, 66, pp. 221–230.

Abstract

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 . We present a complete solution to this problem for .