This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A091073 #13 Mar 18 2017 16:13:46 %S A091073 1,2,8,39,242,1895,19051,246895,4145108,90325655,2555630036, %T A091073 93810648902,4461086120602,274339212258846,21775814889230580, %U A091073 2226876304576948549 %N A091073 Number of transitive relations on n unlabeled points. %C A091073 a(13)-a(15) are from Brinkmann's and McKay's paper. - _Vladeta Jovovic_, Jan 07 2006 %H A091073 Gunnar Brinkmann and Brendan D. McKay, <a href="http://users.cecs.anu.edu.au/~bdm/papers/topologies.pdf">Counting unlabelled topologies and transitive relations</a>. %H A091073 Gunnar Brinkmann and Brendan D. McKay, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL8/McKay/mckay170.html">Counting Unlabelled Topologies and Transitive Relations</a>, Journal of Integer Sequences, Vol. 8 (2005), Article 05.2.1. %H A091073 G. Pfeiffer, <a href="http://schmidt.nuigalway.ie/~goetz/pub/posetseq.html">Counting Transitive Relations</a>, preprint, 2004. %H A091073 G. Pfeiffer, <a href="http://www.cs.uwaterloo.ca/journals/JIS/VOL7/Pfeiffer/pfeiffer6.html">Counting Transitive Relations</a>, Journal of Integer Sequences, Vol. 7 (2004), Article 04.3.2. %Y A091073 Cf. A079265 (antisymmetric transitive relations), A001930 (reflexive transitive relations), A000112 (partial orders), A006905 (labeled transitive relations). %K A091073 hard,nonn,nice %O A091073 0,2 %A A091073 Goetz Pfeiffer (goetz.pfeiffer(AT)nuigalway.ie), Jan 21 2004 %E A091073 More terms from _Vladeta Jovovic_, Jan 07 2006