Properties of the Steiner Triple Systems of Order 19

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Date

Keywords

Automorphism; Chromatic index; Chromatic number; Configuration; Cycle structure; Existential closure; Independent set; Partial parallel class; Rank; Steiner triple system of order 19

Degree Level

Advisor

Degree Name

Volume

17

Issue

R98

Publisher

Electronic Journal of Combinatorics

Abstract

Properties of the 11 084 874 829 Steiner triple systems of order 19 are examined. In particular, there is exactly one 5-sparse, but no 6-sparse, STS(19); there is exactly one uniform STS(19); there are exactly two STS(19) with no almost parallel classes; all STS(19) have chromatic number 3; all have chromatic index 10, except for 4 075 designs with chromatic index 11 and two with chromatic index 12; all are 3-resolvable; and there are exactly two 3-existentially closed STS(19).