2 problems

Let $cmathfrak{S}_n$ be the symmetric group on $n$ letters, and let $p_n$ denote the $n$-th powered Catalan number. Let $cmathfrak{S}_n(\underline{23}14)$ be the permutations avoid…

Let $cmathbf{I}_n$ be the set of inversion sequences of length $n$, and let $cmathcal{PA}_n$ be the set of primitive ascent sequences of length $n$. For an inversion sequence $e$,…