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A059083
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Number of T_0-antichains on a labeled n-set.
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7
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OFFSET
| 0,1
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COMMENTS
| 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.
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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.
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LINKS
| V. Jovovic, 3-element T_0-antichains on a labeled 4-set
V. Jovovic, Formula for the number of m-element T_0-antichains on a labeled n-set
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FORMULA
| a(n)=Sum_{m=0..binomial(n, floor(n/2))} A(m, n), where A(m, n) is number of m-element T_0-antichains on a labeled n-set. Cf. A059080.
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EXAMPLE
| a(0) = 1 + 1, a(1) = 1 + 2, a(2) = 2 + 1, a(3) = 6 + 2, a(4) = 12 + 52 + 25 + 6 + 1, a(5) = 520 + 1770 + 2086 + 1370 + 490 + 115 + 20 + 2. a(n) = column sums of A059080.
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CROSSREFS
| Cf. A059079-A059082, A059048-A059052.
Cf. A000372.
Sequence in context: A108692 A157126 A166994 * A124931 A124932 A194232
Adjacent sequences: A059080 A059081 A059082 * A059084 A059085 A059086
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KEYWORD
| hard,nonn
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AUTHOR
| Vladeta Jovovic, Goran Kilibarda (vladeta(AT)eunet.rs), Jan 06 2001
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EXTENSIONS
| More terms from Vladeta Jovovic (vladeta(AT)eunet.rs), Nov 28 2003
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