Double-star snark
Introduction In the mathematical field of graph theory, the '''double-star snark''' is a snark with 30 vertices and 45 edges.In 1975,  Rufus Isaacs introduced two infinite families of snarks—the flower snark and the BDS snark, a family that includes the two Blanuša snarks, the Descartes snark and the Szekeres snark (BDS stands for Blanuša Descartes Szekeres). Isaacs also discovered one 30-vertex snark that does not belong to the BDS family and that is not a flower snark — the double-star snark.As a snark, the double-star graph is a connected, bridgeless cubic graph with chromatic index equal to 4.The double-star snark is non-planar and non-hamiltonian but is hypohamiltonian. It has book thickness 3 and queue number 2.
Gallery Image:Double-star snark 3COL.svg|The chromatic number of the double-star snark is 3.Image:Double-star snark 4color edge.svg|The chromatic index of the double-star snark is 4.
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