%I
%S 1,1,1,3,12,90,2162,179098,51110788,48762860958,157117982629089,
%T 1735975636147643118,66687671220840028265672,
%U 9012793558387399546070260538,4328655012123103085159161399497333,7451986601800967792474321528025564017244,46329541711597124247394557123740768918978380463
%N Number of connected loopfree Eulerian digraphs with n nodes.
%C Assumed to be weakly connected.
%D F. Harary and E. M. Palmer, Graphical Enumeration, Academic Press, NY, 1973, p. 219 (but there is an error).
%D R. C. Read (rcread(AT)math.uwaterloo.ca), email to _N. J. A. Sloane_, 28 August, 2000.
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/EulerianGraph.html">Eulerian Graph</a>
%F Inverse Euler transform of A058338.  _Andrew Howroyd_, Apr 12 2020
%Y Cf. A058338.
%K nonn,nice,hard
%O 0,4
%A _N. J. A. Sloane_
%E a(7) (generated graphs with nauty, filtered and counted with Python) by _Pietro Battiston_, Feb 08 2014
%E a(8) and a(9) added and description clarified by _Brendan McKay_, May 05 2019
%E Terms a(10) and beyond from _Andrew Howroyd_, Apr 12 2020
