Abstract We define a bijection between permutations and valued Dyck paths, namely, Dyck paths whose odd vertices are labelled with an integer that does not exceed their height. This map allows us to characterize the set of permutations avoiding the pattern 132 as the preimage of the set of Dyck paths with minimal labeling. Moreover, exploiting this bijection we associate to the set of n-permutations a polynomial that generalizes at the same time Eulerian polynomials, Motzkin numbers, super-Catalan numbers, little Schr¨oder numbers, and other combinatorial sequences. Lastly, we determine the Hankel transform of the sequence of such polynomials.
Barnabei, M., Bonetti, F., Castronuovo, N., Silimbani, M. (2019). Ascending runs in permutations and valued Dyck paths. ARS MATHEMATICA CONTEMPORANEA, 16(2), 445-463 [10.26493/1855-3974.1679.ad3].
Ascending runs in permutations and valued Dyck paths
Barnabei, Marilena
;Bonetti, Flavio;Castronuovo, Niccolò;Silimbani, Matteo
2019
Abstract
Abstract We define a bijection between permutations and valued Dyck paths, namely, Dyck paths whose odd vertices are labelled with an integer that does not exceed their height. This map allows us to characterize the set of permutations avoiding the pattern 132 as the preimage of the set of Dyck paths with minimal labeling. Moreover, exploiting this bijection we associate to the set of n-permutations a polynomial that generalizes at the same time Eulerian polynomials, Motzkin numbers, super-Catalan numbers, little Schr¨oder numbers, and other combinatorial sequences. Lastly, we determine the Hankel transform of the sequence of such polynomials.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.