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Graph TheoryHardWalks, Paths and Connectivity

Walks, Paths and Connectivity · Hard problem

Let GG be two triangles sharing a single vertex: one on vertices 1,2,31,2,3 and the other on vertices 1,4,51,4,5 (vertex 11 is the shared vertex, and there is no edge 2323 or 4545 beyond the triangle sides). How many closed walks of length 44 start and end at vertex 22?