A292852 Spherical congruence-uniform lattices on n unlabeled nodes

1, 1, 0, 1, 1, 2, 3, 8, 17, 45, 123, 367, 1148, 3792

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

Table of n, a(n) for n=1..14.

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

Cf. A292790.

Sequence in context: A319566 A294450 A345243 * A148014 A148015 A148016

Adjacent sequences: A292849 A292850 A292851 * A292853 A292854 A292855

Keyword

nonn,more

Author

Henri Mühle, Sep 25 2017

Extensions

a(13)-a(14) from Henri Mühle, Aug 29 2019

Status

approved