%I
%S 1,1,2,12,185,8990,1505939,875542491
%N Number of digraphs on n unlabeled nodes with a sink (or, with a source).
%C Here a sink is defined to be a node to which all other nodes have a directed path.  _Andrew Howroyd_, Dec 27 2021
%D F. Harary and E. M. Palmer, Graphical Enumeration, Academic Press, NY, 1973, p. 218 (incorrect version).
%D R. C. Read (rcread(AT)math.uwaterloo.ca), email to _N. J. A. Sloane_, 28 August, 2000.
%Y The labeled case is A003028.
%Y Cf. A049531.
%K nonn,nice,more
%O 0,3
%A _Vladeta Jovovic_
%E a(6) corrected and a(7) from _Sean A. Irvine_, Sep 11 2021
