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A224886 Number of unlabeled tournaments which do not contain a transitive n-tournament. 1
0, 1, 2, 4, 13 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,3
COMMENTS
The empty tournament is considered.
LINKS
John W. Moon, Topics on tournaments, Holt, Rinehard and Winston (1968).
EXAMPLE
For n=4, the a(4)= 13 solutions are the 5 tournaments on at most three vertices (the empty tournament is counted), 3 tournaments on four vertices, 3 tournaments on five vertices, 1 tournament on seven vertices (the Paley tournament on P_7 on seven vertices) and 1 tournament on six vertices (the tournament obtained from P_7 by deleting one vertex).
Notice that the tournaments on at most six vertices are listed in the Moon reference.
CROSSREFS
Sequence in context: A287059 A059085 A030064 * A180500 A176990 A109928
KEYWORD
nonn,more
AUTHOR
Houmem Belkhechine, Jul 24 2013
STATUS
approved

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Last modified June 19 18:58 EDT 2024. Contains 373507 sequences. (Running on oeis4.)