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 A319624 #6 Oct 26 2018 12:50:18 %S A319624 1,1,0,1,5,63 %N A319624 Number of non-isomorphic connected antichain covers of n vertices by distinct sets whose dual is also an antichain of distinct sets. %C A319624 The dual of a multiset partition has, for each vertex, one block consisting of the indices (or positions) of the blocks containing that vertex, counted with multiplicity. For example, the dual of {{1,2},{2,2}} is {{1},{1,2,2}}. %e A319624 Non-isomorphic representatives of the a(1) = 1 through a(4) = 5 antichain covers: %e A319624 1: {{1}} %e A319624 3: {{1,2},{1,3},{2,3}} %e A319624 4: {{1,2},{1,3},{2,4},{3,4}} %e A319624 {{1,2},{1,3},{1,4},{2,3,4}} %e A319624 {{1,3},{1,4},{2,3},{2,4},{3,4}} %e A319624 {{1,2,3},{1,2,4},{1,3,4},{2,3,4}} %e A319624 {{1,2},{1,3},{1,4},{2,3},{2,4},{3,4}} %Y A319624 Cf. A006126, A007716, A007718, A056156, A059201, A283877, A316980, A316983, A318099, A319557, A319558, A319565, A319616-A319646, A300913. %K A319624 nonn,more %O A319624 0,5 %A A319624 _Gus Wiseman_, Sep 25 2018