### Blog Stats

- 16,021 hits

### Last visits

- 3-edge coloring 4 4 color theorem 4ct Alfred Bray Kempe algorithm Brendan McKay Cahit spiral chains color coloring coloring maps colour cubic graphs different edge embedding Euler four Four color four color music four color problem four colors suffice four color theorem Francis Guthrie Fullerene graph graph coloring Graph isomorphism graphs representations Graph theory Gunnar Brinkmann Hamilton homeomorphic impasse isomorphic graphs Java Kempe Kempe chain Kenneth Appel map new features oeis pencil and paper plantri problem proof proper colorings sage sagemath tait Tait coloring theorem tutte Wolfgang Haken
### Blogroll

### Comments

stefanutti on Quotes Todd Gibson on Quotes G.A. on Four color theorem: new i… Four color theorem:… on Four color theorem: back to th… Question about 3-reg… on Four color theorem: simplified… G.A. on Abstract Four color theorem:… on Four color theorem: counterexa… stefanutti on Four color theorem: representa… Guy on Four color theorem: representa… Brian Gordon on Four color theorem: 3-edge col… ### Meta

# Tag Archives: coloring maps

## Four color theorem: experimenting impasses (as in life)

I still think a solution may be found in Kempe chain color swapping … for maps without F2, F3 and F4 faces (or even without this restriction). Or at least I want to try. How you can solve the impasses … Continue reading

Posted in math
Tagged 3-edge coloring, 4ct, coloring maps, four color problem, Kempe chain, Tait coloring
Leave a comment

## Four color theorem: work in progress

😦 Too many more things to do and little time: Filter out duplicates. I finally found a java library to efficiently filter out all isomorphic graphs. It is a library part if the sspace project. Using it I will be able … Continue reading

Posted in math
Tagged 4ct, Cahit spiral chains, coloring maps, four color theorem, Graph theory, tait, Tait coloring
Leave a comment

## Four color theorem: Cahit spiral chains (step two)

Now the application is able to find all spiral chains of a graph. I still need to: Implement the Cahit coloring algorithm using the spiral chains Add some additional features to the Java application Modify the settings to color the … Continue reading

Posted in Uncategorized
Tagged 4ct, Cahit spiral chains, coloring maps, Four color, Tait coloring
Leave a comment

## Four color theorem: videos

Four videos for the four color theorem. music coloring algorithm slow motion maps java application features

Posted in math
Tagged coloring maps, four color problem, four color theorem, graph coloring, pencil and paper
Leave a comment

## Four color theorem: other representations of maps

Here are some new representation of graphs: Thanks to: http://mathoverflow.net/questions/63861/representations-of-regular-maps-four-color-theorem http://www.geogebra.org/forum/viewtopic.php?f=2&t=21841

## Four color theorem: representations of maps

For the scope of the four color problem and without lack of generality, maps can be represented in different ways. This is generally done to have a different perspective on the problem. For example, the graph-theoretic representation of maps has … Continue reading

## Counting maps

I’ve posted this question on mathoverflow. Is there a formula to count how many different topological regular maps can be created with n faces (on a sphere)? For “regular” I intend maps in which the boundaries form a 3-regular planar … Continue reading