2019/04/02 by Igor Pak, Pak, Igor · 1 citation
Chemistry · #05-02 #05A10 #05A20 (Primary) #05E10 (Secondary) #Combinatorics (math.CO) #Discrete Mathematics (cs.DM) #FOS: Computer and information sciences #FOS: Mathematics #History and advancements in chemistry
paper · pdf · doi:10.48550/arxiv.1904.01656
openalex publication_date 2019/04/02 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
This is an expanded version of the Notices of the AMS column with the same title. The text is unchanged, but we added acknowledgements and a large number of endnotes which provide the context and the references.