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A304996 Number of unlabeled antichains of finite sets spanning up to n vertices with singleton edges allowed. 10
1, 2, 6, 24, 166, 3266, 826308 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
LINKS
EXAMPLE
Non-isomorphic representatives of the a(3) = 24 antichains:
{}
{{1}}
{{1,2}}
{{1,2,3}}
{{1},{2}}
{{2},{1,2}}
{{3},{1,2}}
{{3},{1,2,3}}
{{1,3},{2,3}}
{{1},{2},{3}}
{{1},{2},{1,2}}
{{2},{3},{1,3}}
{{2},{3},{1,2,3}}
{{3},{1,2},{2,3}}
{{3},{1,3},{2,3}}
{{1,2},{1,3},{2,3}}
{{1},{2},{3},{2,3}}
{{1},{2},{3},{1,2,3}}
{{2},{3},{1,2},{1,3}}
{{2},{3},{1,3},{2,3}}
{{3},{1,2},{1,3},{2,3}}
{{1},{2},{3},{1,3},{2,3}}
{{2},{3},{1,2},{1,3},{2,3}}
{{1},{2},{3},{1,2},{1,3},{2,3}}
CROSSREFS
Partial sums of A304997.
Sequence in context: A012361 A308111 A121773 * A012711 A356579 A352059
KEYWORD
nonn,more
AUTHOR
Gus Wiseman, May 23 2018
EXTENSIONS
a(5)-a(6) from Andrew Howroyd, Aug 14 2019
STATUS
approved

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Last modified July 15 06:58 EDT 2024. Contains 374324 sequences. (Running on oeis4.)