A037843 Number of matrices with n columns whose rows do not cover each other; ordered antichains of subsets of an n-set.

2, 3, 7, 39, 2551, 22928343, 6641112790058484007

Offset: 0

Author

Vladeta Jovovic, Goran Kilibarda, Jul 23 2000

Keywords

• hard
• nonn

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

• K. S. Brown, Dedekind's problem
• Index entries for sequences related to Boolean functions

Crossrefs

Cf. A003182, A051112-A051117, A007411, A006602.

Formula

a(n)=Sum_{k=0..C(n, floor(n/2))}k!*M(n, k) where M(n, k) is the number of distinct monotone Boolean functions of n variables with k mincuts.