Existence of 4-GDDs with at most 50 points and 4-GDDs of types 6 3 and 9 3

Autor: Yudhistira A. Bunjamin, R. Julian R. Abel, Diana Combe
Rok vydání: 2021
Předmět:
Zdroj: Discrete Mathematics. 344:112479
ISSN: 0012-365X
DOI: 10.1016/j.disc.2021.112479
Popis: In this paper we give two new refinements to the known necessary conditions for the existence of a 4-GDD and list all the feasible group types for 4-GDDs where the number of points v satisfies 31 ≤ v ≤ 50 . For v in this range, we obtain solutions for all feasible group types when v ≡ 0 ( mod 3 ) , and solutions for all feasible types of the form 4 s 1 t w 1 except 4 8 1 1 10 1 . We also obtain various other 4-GDDs. These include solutions for 4-GDDs of types 6 s 3 t and 9 s 3 t for all but a finite number of feasible values of s and t.
Databáze: OpenAIRE