Title
Enumeration of the doubles of the projective plane of order 4
Abstract
A classification of the doubles of the projective plane of order 4 with respect to the order of the automorphism group is presented and it is established that, up to isomorphism, there are 1746461307 doubles. We start with the designs possessing non-trivial automorphisms. Since the designs with automorphisms of odd prime orders have been constructed previously, we are left with the construction of the designs with automorphisms of order 2. Moreover, we establish that a 2-(21,5,2) design cannot be reducible in two inequivalent ways. This makes it possible to calculate the number of designs with only the trivial automorphism, and consequently the number of all double designs. Most of the computer results are obtained by two different approaches and implementations.
Year
DOI
Venue
2006
10.1016/j.disc.2006.05.007
Discrete Mathematics
Keywords
Field
DocType
construction methods,double design,projective plane
Prime (order theory),Discrete mathematics,Automorphism group,Combinatorics,Automorphisms of the symmetric and alternating groups,Automorphism,Enumeration,Isomorphism,Projective plane,Construction method,Mathematics
Journal
Volume
Issue
ISSN
306
18
Discrete Mathematics
Citations 
PageRank 
References 
0
0.34
3
Authors
4
Name
Order
Citations
PageRank
Veerle Fack18411.22
Svetlana Topalova2258.30
Joost Winne3212.71
Rosen Zlatarski450.97