In the mathematical field of graph theory, the Watkins snark is a snark with 50 vertices and 75 edges.^[1][2] It was discovered by John J. Watkins in 1989.^[3]

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. It has book thickness 3 and queue number 2.^[4]

Another well known snark on 50 vertices is the Szekeres snark, the fifth known snark, discovered by George Szekeres in 1973.^[5]

• The chromatic number of the Watkins snark is 3.
• The chromatic index of the Watkins snark is 4.

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