# Combinatorial Data

This page contains some collections of combinatorial data.

Other useful resources include:

#### Graph formats

Unless otherwise specified, graphs are presented in either
**graph6** or **sparse6** format.
The extension on the file name (.g6 or .s6) indicates
which is used in each case.
See here for information on how
to use these formats.
Large files are gzipped and have an additional .gz extension.

#### License

Except where it is indicated that the data was compiled by
someone else, Brendan McKay releases all the data files (but not
the html files) in this collection under the
Creative
Commons Attribution 4.0 International (CY BY 4.0) license.

## Various simple graphs

The graphs page has some collections
of general graphs, eulerian graphs, chordal graphs,
strongly regular graphs,
Ramsey graphs, hypohamiltonian graphs, planar graphs,
self-complementary graphs, highly irregular graphs,
and circulant graphs.

## Directed graphs

Some tournaments, self-complementary tournaments,
locally-transitive tournaments, Ramsey tournaments, vertex-transitive tournaments,
acyclic directed graphs, and posets are
available on the digraphs page.

## Various plane graphs

The plane graphs page has some
graphs imbedded in the plane that are hard to make using
plantri.

## Trees

The trees page has some small trees
classified by order and diameter.

## Greechie diagrams

Greechie diagrams are a particular sort of hypergraph used in
quantum physics to represent orthomodular lattices.
They have their own page.

## Latin squares and cubes

The Latin squares page has the Latin
squares of small order.

The Latin cubes page has the Latin
cubes and hypercubes of small order.

## Hadamard matrices

The Hadamard matrix page has the
Hadamard matrices up to order 32.

## Multigraphs

Some counts of regular multigraphs appear on the
integer matrix page.

## Maximum dissociated sets of 0-1 vectors

The dissociated sets page contains
some of these things that occur in weighing problems.

Page Master: Brendan McKay,
brendan.mckay@anu.edu.au and
https://users.cecs.anu.edu.au/~bdm.