

A292790


Congruenceuniform lattices on n unlabeled nodes


2



1, 1, 1, 2, 4, 9, 22, 60, 174, 534, 1720, 5767, 20013, 71545
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,4


COMMENTS

A lattice is congruenceuniform if it can be constructed from the singletonlattice by a sequence of interval doublings.


LINKS

Table of n, a(n) for n=1..14.
A. Day, Characterizations of finite lattices that are boundedhomomorphic images or sublattices of free lattices, Canadian Journal of Mathematics, 31 (1979), 617631.
H. Mühle, On the lattice property of shard orders, arXiv:1708.02104 [math.CO], 2017.


CROSSREFS

Sequence in context: A294281 A293854 A271078 * A278691 A159329 A159334
Adjacent sequences: A292787 A292788 A292789 * A292791 A292792 A292793


KEYWORD

nonn,more


AUTHOR

Henri Mühle, Sep 25 2017


EXTENSIONS

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


STATUS

approved



