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A319719
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Number of non-isomorphic connected antichains of multisets of weight n.
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24
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1, 1, 3, 4, 10, 14, 48, 95, 305, 822, 2615
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OFFSET
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0,3
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COMMENTS
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In an antichain, no part is a proper submultiset of any other. The weight of an antichain is the sum of sizes of its parts. Weight is generally not the same as number of vertices. Connected antichains are also called clutters.
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LINKS
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EXAMPLE
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Non-isomorphic representatives of the a(1) = 1 through a(4) = 10 connected antichains:
1: {{1}}
2: {{1,1}}
{{1,2}}
{{1},{1}}
3: {{1,1,1}}
{{1,2,2}}
{{1,2,3}}
{{1},{1},{1}}
4: {{1,1,1,1}}
{{1,1,2,2}}
{{1,2,2,2}}
{{1,2,3,3}}
{{1,2,3,4}}
{{1,1},{1,1}}
{{1,2},{1,2}}
{{1,2},{2,2}}
{{1,3},{2,3}}
{{1},{1},{1},{1}}
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CROSSREFS
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Cf. A001055, A001970, A007716, A007718, A056156, A096827, A253249, A285573, A293994, A318099, A319557, A319616-A319646, A319721.
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KEYWORD
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nonn,more
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AUTHOR
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STATUS
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approved
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