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A321679 Number of non-isomorphic weight-n antichains (not necessarily strict) of sets. 9
1, 1, 3, 5, 12, 19, 45, 75, 170, 314, 713 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,3
COMMENTS
The weight of a multiset partition is the sum of sizes of its parts. Weight is generally not the same as number of vertices.
LINKS
EXAMPLE
Non-isomorphic representatives of the a(1) = 1 through a(5) = 19 antichains:
{{1}} {{1,2}} {{1,2,3}} {{1,2,3,4}} {{1,2,3,4,5}}
{{1},{1}} {{1},{2,3}} {{1,2},{1,2}} {{1},{2,3,4,5}}
{{1},{2}} {{1},{1},{1}} {{1},{2,3,4}} {{1,2},{3,4,5}}
{{1},{2},{2}} {{1,2},{3,4}} {{1,4},{2,3,4}}
{{1},{2},{3}} {{1,3},{2,3}} {{1},{1},{2,3,4}}
{{1},{1},{2,3}} {{1},{2,3},{2,3}}
{{1},{2},{3,4}} {{1},{2},{3,4,5}}
{{1},{1},{1},{1}} {{1},{2,3},{4,5}}
{{1},{1},{2},{2}} {{1},{2,4},{3,4}}
{{1},{2},{2},{2}} {{1},{1},{1},{2,3}}
{{1},{2},{3},{3}} {{1},{2},{2},{3,4}}
{{1},{2},{3},{4}} {{1},{2},{3},{4,5}}
{{1},{1},{1},{1},{1}}
{{1},{1},{2},{2},{2}}
{{1},{2},{2},{2},{2}}
{{1},{2},{2},{3},{3}}
{{1},{2},{3},{3},{3}}
{{1},{2},{3},{4},{4}}
{{1},{2},{3},{4},{5}}
CROSSREFS
Sequence in context: A341710 A024458 A143643 * A266819 A245939 A089292
KEYWORD
nonn,more
AUTHOR
Gus Wiseman, Nov 16 2018
STATUS
approved

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Last modified April 19 08:45 EDT 2024. Contains 371782 sequences. (Running on oeis4.)