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 A326574 #6 Aug 13 2019 15:44:57
%S A326574 2,3,5,10,22,61,247,2096,81896,52260575
%N A326574 Number of antichains of subsets of {1..n} with equal edge-sums.
%C A326574 An antichain is a finite set of finite sets, none of which is a subset of any other. The edge-sums are the sums of vertices in each edge, so for example the edge sums of {{1,3},{2,5},{3,4,5}} are {4,7,12}.
%e A326574 The a(0) = 2 through a(4) = 22 antichains:
%e A326574 {} {} {} {} {}
%e A326574 {{}} {{}} {{}} {{}} {{}}
%e A326574 {{1}} {{1}} {{1}} {{1}}
%e A326574 {{2}} {{2}} {{2}}
%e A326574 {{1,2}} {{3}} {{3}}
%e A326574 {{1,2}} {{4}}
%e A326574 {{1,3}} {{1,2}}
%e A326574 {{2,3}} {{1,3}}
%e A326574 {{1,2,3}} {{1,4}}
%e A326574 {{3},{1,2}} {{2,3}}
%e A326574 {{2,4}}
%e A326574 {{3,4}}
%e A326574 {{1,2,3}}
%e A326574 {{1,2,4}}
%e A326574 {{1,3,4}}
%e A326574 {{2,3,4}}
%e A326574 {{1,2,3,4}}
%e A326574 {{3},{1,2}}
%e A326574 {{4},{1,3}}
%e A326574 {{1,4},{2,3}}
%e A326574 {{2,4},{1,2,3}}
%e A326574 {{3,4},{1,2,4}}
%t A326574 stableSets[u_,Q_]:=If[Length[u]==0,{{}},With[{w=First[u]},Join[stableSets[DeleteCases[u,w],Q],Prepend[#,w]&/@stableSets[DeleteCases[u,r_/;r==w||Q[r,w]||Q[w,r]],Q]]]];
%t A326574 cleqset[set_]:=stableSets[Subsets[set],SubsetQ[#1,#2]||Total[#1]!=Total[#2]&];
%t A326574 Table[Length[cleqset[Range[n]]],{n,0,5}]
%Y A326574 Set partitions with equal block-sums are A035470.
%Y A326574 Antichains with different edge-sums are A326030.
%Y A326574 MM-numbers of multiset partitions with equal part-sums are A326534.
%Y A326574 The covering case is A326566.
%Y A326574 Cf. A000372, A003182, A006126, A307249, A321455, A321717, A321718, A326518, A326565, A326572.
%K A326574 nonn,more
%O A326574 0,1
%A A326574 _Gus Wiseman_, Jul 18 2019
%E A326574 a(9) from _Andrew Howroyd_, Aug 13 2019