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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A051421 Number of n-node digraphs with a sink (or, with a source). 5
1, 1, 2, 12, 185, 8990, 1478644 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

REFERENCES

F. Harary and E. M. Palmer, Graphical Enumeration, Academic Press, NY, 1973, p. 218 (incorrect version).

R. C. Read (rcread(AT)math.uwaterloo.ca), email to N. J. A. Sloane, 28 August, 2000.

LINKS

Table of n, a(n) for n=0..6.

CROSSREFS

Sequence in context: A039748 A007764 A015195 * A182162 A258994 A110105

Adjacent sequences:  A051418 A051419 A051420 * A051422 A051423 A051424

KEYWORD

nonn,nice,more

AUTHOR

Vladeta Jovovic

STATUS

approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified November 19 04:22 EST 2018. Contains 317333 sequences. (Running on oeis4.)