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 A322399 #5 Dec 06 2018 16:36:30
%S A322399 0,0,2,12,149
%N A322399 Number of non-isomorphic 2-edge-connected clutters spanning n vertices.
%C A322399 A clutter is a connected antichain of sets. It is 2-edge-connected if it cannot be disconnected by removing any single edge. Compare to blobs or 2-vertex-connected clutters (A304887).
%e A322399 Non-isomorphic representatives of the a(4) = 12 clutters:
%e A322399 {{1,4},{2,3,4}}
%e A322399 {{1,3,4},{2,3,4}}
%e A322399 {{1,4},{2,4},{3,4}}
%e A322399 {{1,3},{1,4},{2,3,4}}
%e A322399 {{1,2},{1,3,4},{2,3,4}}
%e A322399 {{1,2,4},{1,3,4},{2,3,4}}
%e A322399 {{1,2},{1,3},{2,4},{3,4}}
%e A322399 {{1,4},{2,3},{2,4},{3,4}}
%e A322399 {{1,2},{1,3},{1,4},{2,3,4}}
%e A322399 {{1,3},{1,4},{2,3},{2,4},{3,4}}
%e A322399 {{1,2,3},{1,2,4},{1,3,4},{2,3,4}}
%e A322399 {{1,2},{1,3},{1,4},{2,3},{2,4},{3,4}}
%Y A322399 Cf. A002218, A007718, A013922, A030019, A048143, A095983, A304887, A317634, A317635, A317672, A322335, A322394, A322396, A322397.
%K A322399 nonn,more
%O A322399 1,3
%A A322399 _Gus Wiseman_, Dec 06 2018