Six-Color Theorem

To color any map on the Sphere or the Plane requires at most six-colors. This number caneasily be reduced to five, and the Four-Color Theorem demonstrates that the Necessary number is, in fact, four.

References

Franklin, P. ``A Six Colour Problem.'' J. Math. Phys. 13, 363-369, 1934.

Hoffman, I. and Soifer, A. ``Another Six-Coloring of the Plane.'' Disc. Math. 150, 427-429, 1996.

Saaty, T. L. and Kainen, P. C. The Four-Color Problem: Assaults and Conquest. New York: Dover, 1986.

• Euler Polynomial
• Euler Polynomial Identity
• Euler Power Conjecture
• Euler Product
• Euler Pseudoprime
• Euler Quartic Conjecture
• Euler's 6n+1 Theorem
• Euler's Addition Theorem
• Euler's Circle
• Euler's Conjecture
• Euler's Criterion
• Euler's Displacement Theorem
• Euler's Distribution Theorem
• Euler's Factorization Method
• Euler's Finite Difference Transformation
• Euler's Graeco-Roman Squares Conjecture
• Euler's Homogeneous Function Theorem
• Euler's Hypergeometric Transformations
• Euler's Idoneal Number
• Euler's Machin-Like Formula
• Euler's Pentagonal Number Theorem
• Euler's Phi Function
• Euler's Polygon Division Problem
• Euler's Quadratic Residue Theorem
• Euler Square