Invitation: celebrating 50 years of OEIS, 250000 sequences, and Sloane's 75th, there will be a conference at DIMACS, Rutgers, Oct 9-10 2014.
%I
%S 1,1,8,137,7704,1413982
%N Number of n-vertex unlabeled digraphs without endpoints.
%Y Cf. A100548 (labeled case), A004110, A004108, A059166, A059167.
%K more,nonn
%O 1,3
%A Goran Kilibarda, Zoran Maksimovic, _Vladeta Jovovic_, Jan 14 2005