Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #12 Dec 06 2020 17:17:47
%S 1,1,1,7,136,8001,1445297,863488287
%N Number of asymmetric digraphs with n nodes.
%D F. Harary and E. M. Palmer, Graphical Enumeration, Academic Press, NY, 1973, p. 231.
%D P. K. Stockmeyer, The enumeration of graphs with prescribed automorphism group, Dissertation, Univ. of Michigan, Ann Arbor, 1971.
%F a(n) = A000273(n) - A067309(n). - _Andrew Howroyd_, Dec 06 2020
%Y Cf. A000273 (digraphs), A003400 (asymmetric graphs), A030242 (asymmetric relations), A067309.
%K hard,nonn,nice
%O 0,4
%A _Vladeta Jovovic_
%E a(6) from _Christian G. Bower_ Dec 15 1999
%E a(7) from _Andrew Howroyd_, Dec 06 2020