@article{05013499,
title = {Counting upper interactions in Dyck paths.},
journal = {S\'eminaire Lotharingien de Combinatoire [electronic only]},
volume = {53},
year = {2005},
zbl = {1088.05011},
language = {en},
url = {http://dml.mathdoc.fr/item/05013499}
}
Le Borgne, Yvan. Counting upper interactions in Dyck paths.. Séminaire Lotharingien de Combinatoire [electronic only], Tome 53 (2005) . http://gdmltest.u-ga.fr/item/05013499/