2010/10/23 by Marc A. A. Van Leeuwen, Marc Van Leeuwen, Van Leeuwen, Marc A. A. · 1 citation
Mathematics · #Advanced Combinatorial Mathematics #Advanced Topics in Algebra #Algebraic structures and combinatorial models #Combinatorics (math.CO) #FOS: Mathematics #math.CO
paper · pdf · doi:10.48550/arxiv.1010.4847
arxiv created 2010/10/23 · openalex publication_date 2010/10/23 · arxiv updated 2010/10/26 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In this note we observe that a bijection related to Littelmann's root operators (for type A1) transparently explains the well known enumeration by length of walks on \N (left factors of Dyck paths), as well as some other enumerative coincidences. We indicate a relation with bijective solutions of Bertrand's ballot problem: those can be mechanically transformed into bijective proofs of the mentioned enumeration formula.