“…Many articles dealing with the occurrence of strings in Dyck paths have appeared in the literature (e.g. see [1,3,5,8,12,13,14,19,20,21,24]). In particular, it has been proved (see [8]) that the statistic N τ follows the Narayana distribution (A001263 of [23]), for every string τ of length 2, the statistic N udu follows the Donaghey distribution (see [24]) and the statistic N duu follows the Touchard distribution (see [8]).…”