A224886 Number of unlabeled tournaments which do not contain a transitive n-tournament.

0, 1, 2, 4, 13

Offset

0,3

Comments

The empty tournament is considered.

Links

Table of n, a(n) for n=0..4.

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

Adjacent sequences: A224883 A224884 A224885 * A224887 A224888 A224889

Keyword

nonn,more

Author

Houmem Belkhechine, Jul 24 2013

Status

approved