On the covering of t-sets with (t + 1)-sets:C(9, 5, 4) and C(10, 6, 5)
A (υ, k, t) covering system is a pair (X, B) where X is a υ-set of points and B is a family of k-subsets, called blocks, of X such that every t-subset of X is contained in at least one block. The minimum possible number of blocks in a (υ, k, t) covering system is denoted by C(υ, k, t). It is proven that there are exactly three non-isomorphic systems giving C(9, 5, 4) = 30, and a unique system giving C(10, 6, 5) = 50. © 1991.
de Caen, D.,
On the covering of t-sets with (t + 1)-sets:C(9, 5, 4) and C(10, 6, 5).
Retrieved from: https://digitalcommons.mtu.edu/michigantech-p/5242