A186808 Numbers n such that there are a prime number of unlabeled distributive lattices with n elements.

4, 5, 6, 10, 12, 13, 18, 21, 23, 26

Offset

1,1

Comments

A lattice which satisfies the identities:

(x^y)V(x^z) = x^(yVz);

(xVy)^(xVz) = xV(y^z)

is said to be distributive.

References

Gratzer, G. Lattice Theory: First Concepts and Distributive Lattices. San Francisco, CA: W. H. Freeman, pp. 35-36, 1971.

Links

Table of n, a(n) for n=1..10.

Formula

{k: A006982(k) is in A000040}.

Example

a(10) = 26 because there are 711811 unlabeled distributive lattices with 26 elements, and 711811 is a prime number.

Crossrefs

Cf. A000040, A006982

Sequence in context: A024565 A327223 A143833 * A114439 A310570 A271146

Adjacent sequences: A186805 A186806 A186807 * A186809 A186810 A186811

Keyword

nonn

Author

Jonathan Vos Post, Feb 26 2011

Status

approved