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 A306001 #10 Aug 14 2019 01:48:43
%S A306001 1,1,2,8,84,13000
%N A306001 Number of unlabeled intersecting set-systems with no singletons on up to n vertices.
%C A306001 An intersecting set-system S is a finite set of finite nonempty sets (edges), any two of which have a nonempty intersection. A singleton is an edge containing only one vertex.
%F A306001 a(n) = A305856(n) - A000612(n). - _Andrew Howroyd_, Aug 12 2019
%e A306001 Non-isomorphic representatives of the a(3) = 8 set-systems:
%e A306001 {}
%e A306001 {{1,2}}
%e A306001 {{1,2,3}}
%e A306001 {{1,3},{2,3}}
%e A306001 {{2,3},{1,2,3}}
%e A306001 {{1,2},{1,3},{2,3}}
%e A306001 {{1,3},{2,3},{1,2,3}}
%e A306001 {{1,2},{1,3},{2,3},{1,2,3}}
%Y A306001 Cf. A001206, A051185, A048143, A261006, A058891, A261005, A304998, A305854-A305857, A305935, A305999, A306000.
%K A306001 nonn,more
%O A306001 0,3
%A A306001 _Gus Wiseman_, Jun 16 2018
%E A306001 a(5) from _Andrew Howroyd_, Aug 12 2019