Tag Archives: Higman-Sims


The word “solutions” is much overused, even misused, now. When I see a van with “Cleaning solutions” on the side, I imagine it full of containers of ammonia or soapy water, while “Printing solutions” can only mean ink … But … Continue reading

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The prehistory of the Higman-Sims graph

Triangle-free strongly regular graphs form a fascinating byway of combinatorics. These are regular graphs of valency k on v vertices, which contain no triangles, and have the property that any two non-adjacent vertices have μ common neighbours. The numbers (v,k,μ) … Continue reading

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