@article {IOPORT.05869064,
    author       = {Manes, K. and Sapounakis, A. and Tasoulas, I. and Tsikouras, P.},
    title        = {Counting strings at height $j$ in Dyck paths.},
    year         = {2011},
    journal      = {Journal of Statistical Planning and Inference},
    volume       = {141},
    number       = {6},
    issn         = {0378-3758},
    pages        = {2100-2107},
    publisher    = {Elsevier Science B.V. (North-Holland), Amsterdam},
    doi          = {10.1016/j.jspi.2010.12.022},
    abstract     = {Summary: Let $\tau $ be an arbitrary lattice path, called in this context string, consisting of two kinds of steps (rises and falls) and let $j$ be a non-negative integer. In this paper, the explicit formula for the generating function $F_j$ associated with the Dyck path statistic ``number of occurrences of $\tau $ at height $j$'' is evaluated. For the expression of $F_j$ some basic characteristics of the string are used, namely its number of rises, height, depth and periodicity, as well as the generating function of the Catalan numbers.},
    identifier   = {05869064},
}