A255599 Number of (semi-)regular tournaments of order n.

1, 1, 1, 1, 1, 5, 3, 85, 15, 13333, 1223, 19434757, 1495297, 276013571133, 18400989629

Offset: 1

Author

Danny Rorabaugh, Feb 27 2015

Keywords

• nonn
• hard
• more

Comments

A tournament of odd order n is regular if the out-degree of each vertex is (n-1)/2. A tournament of even order n is semi-regular if the out-degree of each vertex is n/2-1 or n/2.

Links

• B. McKay, Digraphs

Crossrefs

Cf. A000568, A096368.

Extensions

a(1)-a(2) prepended and a(14)-a(15) added by Brendan McKay, Mar 21 2019