OFFSET
1,6
COMMENTS
A lattice is congruence-uniform if it can be constructed from the singleton-lattice by a sequence of interval doublings. A lattice is spherical if its Möbius function between least and greatest element equals 1 or -1.
LINKS
A. Day, Characterizations of finite lattices that are bounded-homomorphic images or sublattices of free lattices, Canadian Journal of Mathematics, 31 (1979), 617-631.
H. Mühle, On the lattice property of shard orders, arXiv:1708.02104 [math.CO], 2017.
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Henri Mühle, Sep 25 2017
EXTENSIONS
a(13)-a(14) from Henri Mühle, Aug 29 2019
STATUS
approved