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 A286520 #25 Jul 26 2017 10:20:12
%S A286520 1,1,1,1,1,1,1,1,1,1,2,1,1,1,1,1,2,1,2,1,1,1,3,1,1,1,2,1,5,1,1,1,1,1,
%T A286520 5,1,1,1,3,1,5,1,2,2,1,1,4,1,2,1,2,1,3,1,3,1,1,1,17,1,1,2,1,1,5,1,2,1,
%U A286520 5,1,9,1,1,2,2,1,5,1,4,1,1,1,17,1,1,1
%N A286520 Number of finite connected sets of pairwise indivisible positive integers greater than one with least common multiple n.
%C A286520 Given a finite set S of positive integers greater than one, let G(S) be the simple labeled graph with vertex set S and edges between any two vertices that are not relatively prime. For example, G({6,14,15,35}) is a 4-cycle. A set S is said to be connected if G(S) is a connected graph.
%e A286520 The a(30)=5 sets are: {30}, {6,10}, {6,15}, {10,15}, {6,10,15}.
%t A286520 zsm[s_]:=With[{c=Select[Tuples[Range[Length[s]],2],And[Less@@#,GCD@@s[[#]]]>1&]},If[c==={},s,zsm[Union[Append[Delete[s,List/@c[[1]]],LCM@@s[[c[[1]]]]]]]]];
%t A286520 Table[Length[Select[Subsets[Rest[Divisors[n]]],And[!MemberQ[Tuples[#,2],{x_,y_}/;And[x<y,Divisible[y,x]]],zsm[#]==={n}]&]],{n,2,20}]
%Y A286520 Cf. A048143, A054921, A076078, A259936, A281116, A285572, A285573, A286518.
%K A286520 nonn
%O A286520 2,11
%A A286520 _Gus Wiseman_, Jul 24 2017