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A051421 Number of n-node digraphs with a sink (or, with a source). 5
1, 1, 2, 12, 185, 8990, 1505939, 875542491 (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..7.

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

EXTENSIONS

a(6) corrected and a(7) from Sean A. Irvine, Sep 11 2021

STATUS

approved

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Last modified December 6 22:42 EST 2021. Contains 349567 sequences. (Running on oeis4.)