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A059048 Triangle A(n,m) of numbers of n-element ordered T_0-antichains on an unlabeled m-set or numbers of T_1-hypergraphs on n labeled nodes with m (not necessary empty) distinct hyperedges (m=0,1,...,2^n). +0
10
1, 1, 1, 2, 1, 0, 0, 1, 2, 1, 0, 0, 0, 2, 13, 26, 22, 8, 1, 0, 0, 0, 0, 25, 354, 1798, 4822, 8028, 9044, 7240, 4224, 1808, 560, 120, 16, 1, 0, 0, 0, 0, 30, 2086, 45512, 461236, 2797785, 11669660, 36369970, 89356260, 179461250, 302225100, 43458923, 0 (list; graph; listen)
OFFSET

0,4

COMMENT

An antichain on a set is a T_0-antichain if for every two distinct points of the set there exists a member of the antichain containing one but not the other point. T_1-hypergraph is a hypergraph which for every ordered pair (u,v) of distinct nodes has a hyperedge containing u but not v.

REFERENCES

V. Jovovic and G. Kilibarda, On the number of Boolean functions in the Post classes F^{mu}_8, Diskretnaya Matematika, 11 (1999), no. 4, 127-138 (translated in Discrete Mathematics and Applications, 9, (1999), no. 6)

V. Jovovic, G. Kilibarda, On enumeration of the class of all monotone Boolean functions, in preparation.

LINKS

V. Jovovic, 3-element unlabeled ordered T_0-antichains"

V. Jovovic, Number A(m,n) of m-element ordered T_0-antichains on an unlabeled n-set

EXAMPLE

[1, 1], [1, 2, 1], [0, 0, 1, 2, 1], [0, 0, 0, 2, 13, 26, 22, 8, 1], .... There are 72 3-element unlabeled ordered T_0-antichains: 2 on 3-set, 13 on 4-set, 26 on 5-set, 22 on 6-set, 8 on 7-set and 1 on 8-set.

CROSSREFS

Cf. A059049-A059052.

Sequence in context: A107628 A152815 A115296 this_sequence A164116 A164118 A124645

Adjacent sequences: A059045 A059046 A059047 this_sequence A059049 A059050 A059051

KEYWORD

nonn

AUTHOR

Vladeta Jovovic, Goran Kilibarda (vladeta(AT)eunet.rs), Dec 19 2000

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Last modified November 30 13:13 EST 2009. Contains 167758 sequences.


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