Pairwise Balanced Designs whose Block Size Set Contains Seven and Thirteen
نویسنده
چکیده
In this paper, we investigate the PBD-closure of sets K with {7, 13} ⊆ K ⊆ {7, 13, 19, 25, 31, 37, 43}. In particular, we show that v ≡ 1 mod 6, v ≥ 98689 implies v ∈ B({7, 13}). As a preliminary result, many new 13-GDDs of type 13q and resolvable BIBD with block size 6 or 12 are also constructed. Furthermore, we show some elements to be not essential in a Wilson bases for the PBD-closed set {v : v ≡ 1 mod 6, v ≥ 7}. Last compiled: June 28, 2005
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