OFFSET
0,5
COMMENTS
Also graphs with non-spanning edge-connectivity 0.
FORMULA
Binomial transform of A327070.
EXAMPLE
The a(4) = 4 edge-sets: {}, {12,34}, {13,24}, {14,23}.
MATHEMATICA
csm[s_]:=With[{c=Select[Subsets[Range[Length[s]], {2}], Length[Intersection@@s[[#]]]>0&]}, If[c=={}, s, csm[Sort[Append[Delete[s, List/@c[[1]]], Union@@s[[c[[1]]]]]]]]];
Table[Length[Select[Subsets[Subsets[Range[n], {2}]], Length[csm[#]]!=1&]], {n, 0, 5}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Gus Wiseman, Sep 01 2019
STATUS
approved