Double-star snark

Double-star snark
Double-star snark
Double-star snark.svg
The Double-star snark
Vertices 30
Edges 45
Chromatic number 3
Chromatic index 4
Properties Snark
Hypohamiltonian
v · mathematical field of graph theory, the double-star snark is a snark with 30 vertices and 45 edges.[1]

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).[2] Isaacs also discovered one 30-vertex snark that does not belongs to the BSD 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.[3]

Gallery

References

  1. ^ Weisstein, Eric W., "Double Star Snark" from MathWorld.
  2. ^ Isaacs, R. (1975), "Infinite families of non-trivial trivalent graphs which are not Tait-colorable", American Mathematical Monthly (Mathematical Association of America) 82 (3): 221–239, doi:10.2307/2319844, JSTOR 2319844 
  3. ^ Weisstein, Eric W., "Hypohamiltonian Graph" from MathWorld.