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{\bf K. Manes, A. Sapounakis, I. Tasoulas and P. Tsikouras}
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{\bf General Results on the Enumeration of Strings in Dyck Paths}
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Let $\tau$ be a fixed lattice path (called in this context string) on
the integer plane, consisting of two kinds of steps. The Dyck path
statistic ``number of occurrences of $\tau$'' has been studied by many
authors, for particular strings only. In this paper, arbitrary
strings are considered. The associated generating function is
evaluated when $\tau$ is a Dyck prefix (or a Dyck suffix).
Furthermore, the case when $\tau$ is neither a Dyck prefix nor a Dyck
suffix is considered, giving some partial results. Finally, the
statistic ``number of occurrences of $\tau$ at height at least $j$''
is considered, evaluating the corresponding generating function when
$\tau$ is either a Dyck prefix or a Dyck suffix.
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