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Graph TheoryHardIsomorphism and Subgraphs

Isomorphism and Subgraphs · Hard problem

The "bull" graph has a triangle on 1,2,31,2,3 (edges 12,13,2312,13,23) plus two pendant edges 1414 and 2525. Out of the 5!=1205!=120 ways to label 55 vertices, how many produce a labeled graph isomorphic to the bull graph?