croXQ[stn_]:=匹配Q[stn,{___,{___,x_,___,y_,___},___、{___、z_、___、t_、___}、___}/;x<z<y<t||z<x<t<y];
csm[s_]:=使用[{c=Select[Tuples[Range[Length[s]],2],And[OrderedQ[#],UnsameQ@@#,Length[Intersection@@s[[#]]>0]&]},如果[c=={},s,csm[Sort[Append[Delete[s,List/@c[[1]]],Union@@s[[c[1]]]]];
bicmpts[stn_]:=csm[并集[stn,{1}],选择[Subsets[stn,{2}],交集@@#={}&],选择[子集[stn,{2}],croXQ]];
表[Length[Select[Subsets[Subsets[Range[n],{2}],And[Union@@#=Range[n],Length[Pimpts[#]]<=1]&]],{n,0,5}]