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A058338 Number of digraphs with indegree = outdegree at each vertex, or Eulerian digraphs (including disconnected graphs) with n nodes. 7
1, 1, 2, 5, 18, 111, 2292, 181519, 51294836, 48814342597 (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. 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.

CROSSREFS

Euler transform of A058337.

Sequence in context: A007769 A174122 A005805 * A006896 A125625 A281532

Adjacent sequences:  A058335 A058336 A058337 * A058339 A058340 A058341

KEYWORD

nonn,nice,more

AUTHOR

N. J. A. Sloane.

EXTENSIONS

a(7) added using A058337 by Falk Hüffner, Dec 03 2015

a(8) and a(9) added using A058337 by Brendan McKay, May 05 2019

STATUS

approved

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Last modified December 9 13:50 EST 2019. Contains 329877 sequences. (Running on oeis4.)