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 A091070 #9 May 23 2015 15:00:49 %S A091070 1,1,2,3,6,8,16,21,41,57,103,140,276 %N A091070 Number of automorphism groups of partial orders on n points. %H A091070 G. Pfeiffer, <a href="http://schmidt.nuigalway.ie/subgroups">Subgroups</a>. %H A091070 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. %e A091070 a(3)=3 because of the 5 partial orders on 3 points, 2 have trivial automorphism group, 2 have an automorphism of order 2 and one has the full symmetric group as its automorphism group; thus 3 different (conjugacy classes of) subgroups occur. %Y A091070 Cf. A000638 (subgroups of the symmetric group), A000112 (partial orders). %K A091070 hard,more,nonn %O A091070 0,3 %A A091070 Goetz Pfeiffer (goetz.pfeiffer(AT)nuigalway.ie), Jan 21 2004