International Journal of Combinatorics
Volume 2010 (2010), Article ID 767361, 17 pages
doi:10.1155/2010/767361
Research Article

Classification of Triangle-Free 223 Configurations

Abdullah Al-Azemi1 and Anton Betten2

1Department of Mathematics, Faculty of Science, Kuwait University, P.O. Box 5969, Safat-13060, Kuwait
2Department of Mathematics, Colorado State University, Fort Collins, CO 80523, USA

Received 20 May 2010; Accepted 29 July 2010

Academic Editor: Laszlo A. Szekely

Copyright © 2010 Abdullah Al-Azemi and Anton Betten. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The 157, 211 triangle-free symmetric 223 configurations are classified and some of their properties are examined. We conclude that each such configuration has a blocking set. Further properties like transitivity on lines, self-duality, and self-polarity are discussed.