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 A322397 #6 Dec 06 2018 16:36:23
%S A322397 0,0,4,71,5927
%N A322397 Number of 2-edge-connected clutters spanning n vertices.
%C A322397 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 (A275307).
%e A322397 The a(3) = 4 clutters:
%e A322397 {{1,3},{2,3}}
%e A322397 {{1,2},{2,3}}
%e A322397 {{1,2},{1,3}}
%e A322397 {{1,2},{1,3},{2,3}}
%Y A322397 Cf. A001187, A013922, A030019, A048143, A095983, A275307, A317634, A317635, A317672, A322335, A322393, A322395, A322399.
%K A322397 nonn,more
%O A322397 1,3
%A A322397 _Gus Wiseman_, Dec 06 2018