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A058337 Connected loop-free Eulerian digraphs with n nodes. 5
1, 1, 1, 3, 12, 90, 2162, 179098, 51110788, 48762860958 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

COMMENTS

Assumed to be weakly connected.

REFERENCES

F. Harary and E. M. Palmer, Graphical Enumeration, Academic Press, NY, 1973, p. 219 (but there is an error).

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..9.

Eric Weisstein's World of Mathematics, Eulerian Graph

CROSSREFS

Cf. A058338.

Sequence in context: A124191 A065087 A305870 * A025503 A263801 A078124

Adjacent sequences:  A058334 A058335 A058336 * A058338 A058339 A058340

KEYWORD

nonn,nice,hard,more

AUTHOR

N. J. A. Sloane

EXTENSIONS

a(7) (generated graphs with nauty, filtered and counted with Python) by Pietro Battiston, Feb 08 2014

a(8) and a(9) added and description clarified by Brendan McKay, May 05 2019

STATUS

approved

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Last modified March 28 07:59 EDT 2020. Contains 333079 sequences. (Running on oeis4.)