A030269 Number of nonisomorphic disconnected partial lattices.

0, 0, 1, 2, 6, 18, 69, 287, 1397, 7634, 46972, 321014, 2416305, 19840547, 176267022, 1681915809, 17127587977, 185127766583

Offset

0,4

Comments

A partial lattice is a poset where every pair of points has a unique least upper (greatest lower) bound or has no upper (lower) bound.

Links

Table of n, a(n) for n=0..17.

Crossrefs

a(n) = A006966(n-2) - A030268(n).

Sequence in context: A150081 A006674 A006389 * A150082 A177470 A060181

Adjacent sequences: A030266 A030267 A030268 * A030270 A030271 A030272

Keyword

nonn,hard

Author

Christian G. Bower, revised Dec 28 2000

Status

approved