|
In the mathematical field of graph theory, the Watkins snark is a snark with 50 vertices and 75 edges.〔Watkins, J. J. and Wilson, R. J. "A Survey of Snarks." In Graph Theory, Combinatorics, and Applications (Ed. Y. Alavi, G. Chartrand, O. R. Oellermann, and A. J. Schwenk). New York: Wiley, pp. 1129-1144, 1991〕 It was discovered by John J. Watkins in 1989.〔Watkins, J. J. "Snarks." Ann. New York Acad. Sci. 576, 606-622, 1989.〕 As a snark, the Watkins graph is a connected, bridgeless cubic graph with chromatic index equal to 4. The Watkins snark is also non-planar and non-hamiltonian. Another well known snark on 50 vertices is the Szekeres snark, the fifth known snark, discovered by George Szekeres in 1973. ==Gallery== Image:Watkins snark 3COL.svg|The chromatic number of the Watkins snark is 3. Image:Watkins snark 4edge color.svg|The chromatic index of the Watkins snark is 4. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Watkins snark」の詳細全文を読む スポンサード リンク
|