In mathematics, you need at most only four different colors to produce a map in which no two adjacent regions have the same color. Utah and Arizona are considered adjacent, but Utah and New Mexico, ...

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Imagine you're a mapmaker, ready to finish your masterpiece map of the world. The only thing left to do is add the colors. But how many colors do you need for the countries if you want to make sure no ...

https://doi.org/10.4169/amer.math.monthly.120.08.733 https://www.jstor.org/stable/10.4169/amer.math.monthly.120.08.733 Abstract After a brief discussion of the ...

As an undergraduate at the University of Chile, Bernardo Subercaseaux took a dim view of using computers to do math. It seemed antithetical to real intellectual discovery. “There’s some instinct or ...

Let G = (V, E) be a strongly connected, aperiodic, directed graph having outdegree 2 at each vertex. A red-blue coloring of G is a coloring of the edges with the colors red and blue such that each ...