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.
Table of n, a(n) for n=0..17.
a(n) = A006966(n-2) - A030268(n).
Sequence in context: A150081 A006674 A006389 * A150082 A177470 A060181
Adjacent sequences: A030266 A030267 A030268 * A030270 A030271 A030272
Christian G. Bower, revised Dec 28 2000