Corteel, SylvieJosuat-Vergès, MatthieuWilliams, Lauren2012-03-052011Corteel, Sylvie, Josuat-Vergès, Matthieu, and Lauren K. Williams. 2011. The Matrix Ansatz, orthogonal polynomials, and permutations. Advances in Applied Mathematics 46(1-4): 209–225.0196-8858http://nrs.harvard.edu/urn-3:HUL.InstRepos:8316218In this paper we outline a Matrix Ansatz approach to some problems of combinatorial enumeration. The idea is that many interesting quantities can be expressed in terms of products of matrices, where the matrices obey certain relations. We illustrate this approach with applications to moments of orthogonal polynomials, permutations, signed permutations, and tableaux.en-USorthogonal polynomialsmomentspermutation tableauxrook placementspermutationssigned permutationscrossingsGenocchi numberscombinatoricsJournal Article2012-03-0510.1016/j.aam.2010.04.009