FACTOID # 22: South Dakota has the highest employment ratio in America, but the lowest median earnings of full-time male employees.
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Encyclopedia > Percy John Heawood

Percy John Heawood (1861-1955) was a British mathematician. He devoted essentially his whole working life to the four colour theorem, a result which he was the first to state explicitly in 1890. It was finally proved in 1976. 1861 is a common year starting on Tuesday. ... 1955 (MCMLV) was a common year starting on Saturday of the Gregorian calendar. ... Example of a four color map The four color theorem states that every possible geographical map can be colored with at most four colors in such a way that no two adjacent regions receive the same colour. ... 1890 was a common year starting on Wednesday (see link for calendar). ...

See also

The Heawood conjecture in graph theory was an expected formula to give the correct upper bound for the number of colors which are sufficient for graph coloring on a surface of a given genus. ... The Heawood graph, of girth 6 In the mathematical field of graph theory, a Heawood graph is the 6-cage, the smallest cubic graph of girth 6. ...

External links

  • MacTutor biography



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