Doubloons and q-secant numbers
Résumé
Based on the evaluation at $t=-1$ of the generating polynomial for the hyperoctahedral group by the number of descents, an observation recently made by Hirzebruch, a new $q$-secant number is derived by working with the Chow-Gessel $q$-polynomial involving the flag major index. Using the doubloon combinatorial model we show that this new $q$-secant number is a polynomial with positive integral coefficients, a property apparently hard to prove by analytical methods.
Domaines
Combinatoire [math.CO]
Origine : Fichiers produits par l'(les) auteur(s)