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
KEYWORD
nonn,more
AUTHOR
Houmem Belkhechine, Jul 24 2013
STATUS
approved