Robert A. Proctor, Matthew J. Willis. Parabolic Catalan numbers count flagged Schur functions and their appearances as type A Demazure characters (key polynomials). Discrete Mathematics & Theoretical Computer Science, 19(3), 2017. [doi]
@article{ProctorW17,
title = {Parabolic Catalan numbers count flagged Schur functions and their appearances as type A Demazure characters (key polynomials)},
author = {Robert A. Proctor and Matthew J. Willis},
year = {2017},
url = {http://dmtcs.episciences.org/4119},
researchr = {https://researchr.org/publication/ProctorW17},
cites = {0},
citedby = {0},
journal = {Discrete Mathematics & Theoretical Computer Science},
volume = {19},
number = {3},
}