login
This site is supported by donations to The OEIS Foundation.

 

Logo

Annual Appeal: Today, Nov 11 2014, is the 4th anniversary of the launch of the new OEIS web site. 70,000 sequences have been added in these four years, all edited by volunteers. Please make a donation (tax deductible in the US) to help keep the OEIS running.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A051337 Number of strongly connected tournaments on n nodes. 2
1, 0, 1, 1, 6, 35, 353, 6008, 178133, 9355949, 884464590, 152310149735, 48234782263293, 28304491788158056, 30964247546702883729, 63468402142317299907481, 244785748571033855024746438 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,5

COMMENTS

A tournament is strongly connected (or strong) if there is a directed path between any pair of points.

REFERENCES

F. Harary and E. M. Palmer, Graphical Enumeration, Academic Press, NY, 1973, p. 127, Eq. (5.2.4);

J. W. Moon, Topics on Tournaments, Holt, NY, 1968.

J. L. Gross and J. Yellen, eds., Handbook of Graph Theory, CRC Press, 2004; p. 523.

LINKS

Table of n, a(n) for n=1..17.

FORMULA

G.f.: = B(x)/(1+B(x)) where B(x) = g.f. for A000568.

CROSSREFS

Cf. A000568, A054946.

Sequence in context: A167579 A030446 A093989 * A192996 A192997 A152128

Adjacent sequences:  A051334 A051335 A051336 * A051338 A051339 A051340

KEYWORD

nonn,nice,easy

AUTHOR

Vladeta Jovovic

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified December 19 18:23 EST 2014. Contains 252239 sequences.