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 A319540 #21 Aug 17 2019 15:24:50
%S A319540 1,1,0,1,2,14,964,3908438
%N A319540 Number of unlabeled 3-uniform hypergraphs spanning n vertices such that every pair of vertices appears together in some block.
%e A319540 Non-isomorphic representatives of the a(5) = 14 hypergraphs:
%e A319540 {{123}{145}{245}{345}}
%e A319540 {{123}{124}{135}{245}{345}}
%e A319540 {{123}{145}{235}{245}{345}}
%e A319540 {{123}{134}{145}{235}{245}{345}}
%e A319540 {{123}{145}{234}{235}{245}{345}}
%e A319540 {{124}{135}{145}{235}{245}{345}}
%e A319540 {{125}{135}{145}{235}{245}{345}}
%e A319540 {{123}{124}{135}{145}{235}{245}{345}}
%e A319540 {{124}{135}{145}{234}{235}{245}{345}}
%e A319540 {{125}{135}{145}{234}{235}{245}{345}}
%e A319540 {{123}{124}{135}{145}{234}{235}{245}{345}}
%e A319540 {{125}{134}{135}{145}{234}{235}{245}{345}}
%e A319540 {{124}{125}{134}{135}{145}{234}{235}{245}{345}}
%e A319540 {{123}{124}{125}{134}{135}{145}{234}{235}{245}{345}}
%Y A319540 The labeled case is A302394.
%Y A319540 Cf. A000665, A006126, A006129, A038041, A299471, A301922, A302374, A306021, A320395, A322451.
%K A319540 nonn,more
%O A319540 0,5
%A A319540 _Gus Wiseman_, Jan 09 2019
%E A319540 a(6)-a(7) from _Andrew Howroyd_, Aug 17 2019