A \(\lambda\)-packing of pairs by quintuples of a \(v\)-set \(V\) is a family of \(5\)-subsets of \(V\) (called blocks) such that every \(2\)-subset of \(V\) occurs in at most \(\lambda\) blocks. The packing number is defined to be the maximum number of blocks in such a \(\lambda\)-packing. These numbers are determined here for \(\lambda \equiv 0 \mod 4\) and all integers \(v \geq 5\) with the exceptions of \((v, \lambda) \in \{(22, 16), (22, 36), (27, 16)\}\).
1970-2025 CP (Manitoba, Canada) unless otherwise stated.