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A317634
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Number of caps (also clutter partitions) of clutters (connected antichains) spanning n vertices.
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11
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OFFSET
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0,4
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COMMENTS
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A kernel of a clutter is the restriction of the edge set to all edges contained within some connected vertex set. A clutter partition is a set partition of the edge set using kernels.
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LINKS
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Table of n, a(n) for n=0..5.
Gus Wiseman, Every Clutter Is a Tree of Blobs, The Mathematica Journal, Vol. 19, 2017.
Gus Wiseman, All clutter partitions of non-isomorphic clutters on 4 vertices.
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EXAMPLE
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The a(3) = 9 clutter partitions:
{{{1,2,3}}}
{{{1,3},{2,3}}}
{{{1,2},{2,3}}}
{{{1,2},{1,3}}}
{{{1,3}},{{2,3}}}
{{{1,2}},{{2,3}}}
{{{1,2}},{{1,3}}}
{{{1,2},{1,3},{2,3}}}
{{{1,2}},{{1,3}},{{2,3}}}
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CROSSREFS
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Cf. A001187, A030019, A048143, A275307, A286520,, A293510, A304717, A317631, A317632, A317635.
Sequence in context: A217145 A266835 A288324 * A198401 A135609 A277422
Adjacent sequences: A317631 A317632 A317633 * A317635 A317636 A317637
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KEYWORD
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nonn,more
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AUTHOR
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Gus Wiseman, Aug 02 2018
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STATUS
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approved
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