cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-3 of 3 results.

A292852 Spherical congruence-uniform lattices on n unlabeled nodes.

Original entry on oeis.org

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

Views

Author

Henri Mühle, Sep 25 2017

Keywords

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

Crossrefs

Cf. A292790.

Extensions

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

A377408 Number of unlabeled semidistributive lattices with n elements.

Original entry on oeis.org

1, 1, 1, 2, 4, 9, 22, 60, 174, 534, 1720, 5767, 20013, 71546
Offset: 1

Views

Author

Ludovic Schwob, Oct 27 2024

Keywords

Comments

The smallest semidistributive lattice that is not congruence-uniform has 14 elements.

Links

Crossrefs

Cf. A006982 (distributive lattices), A292790 (congruence-uniform lattices).

A292853 Congruence-uniform lattices whose alternate order is a lattice.

Original entry on oeis.org

1, 1, 0, 1, 1, 2, 3, 8, 16, 41, 107, 304, 891, 2735
Offset: 1

Views

Author

Henri Mühle, Sep 25 2017

Keywords

Comments

A lattice is congruence-uniform if it can be constructed from the singleton-lattice by a sequence of interval doublings. This doubling process gives rise to an alternate way of ordering the lattice elements. See the references for more details.

Links

Crossrefs

Cf. A292790, A292852.

Extensions

a(13)-a(14) from Henri Mühle, Aug 29 2019
Showing 1-3 of 3 results.

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