A059079 Number of n-element T_0-antichains on a labeled set.

2, 5, 19, 16654, 2369110564675, 5960531437586238714806902334250676, 479047836152505670895481840783987408043359908583921478726185296900312296071642855730299

Offset

0,1

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.

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

Table of n, a(n) for n=0..6.

Vladeta Jovovic, Illustration

Example

a(0) = (1/0!)*[1!*e] = 2; a(1) = (1/1!)*[2!*e] = 5; a(2) = (1/2!)*([4!*e] - 2*[3!*e] + [2!*e]) = 19; a(3) = (1/3!)*([8!*e] - 6*[6!*e] + 6*[5!*e] + 3*[4!*e] - 6*[3!*e] + 2*[2!*e]) = 16654, where [n!*e]=floor(n!*exp(1)).

Crossrefs

Cf. A059080-A059083, A059048-A059052, A000522.

Sequence in context: A187602 A260140 A270556 * A177494 A136900 A136898

Adjacent sequences: A059076 A059077 A059078 * A059080 A059081 A059082

Keyword

hard,nonn

Author

Vladeta Jovovic, Goran Kilibarda, Dec 23 2000

Status

approved