Rationality, irrationality, and Wilf equivalence in generalized factor order [PDF]
Let $P$ be a partially ordered set and consider the free monoid $P^{\ast}$ of all words over $P$. If $w,w' \in P^{\ast}$ then $w'$ is a factor of $w$ if there are words $u,v$ with $w=uw'v$. Define generalized factor order on $P^{\ast}$ by letting $u \leq
Sergey Kitaev +3 more
doaj +6 more sources
Egge triples and unbalanced Wilf-equivalence [PDF]
Egge conjectured that permutations avoiding the set of patterns $\{2143,3142,\tau\}$, where $\tau\in\{246135,254613,263514,524361,546132\}$, are enumerated by the large Schr\"oder numbers.
Bloom, Jonathan, Burstein, Alex
core +3 more sources
On a refinement of Wilf-equivalence for permutations [PDF]
Recently, Dokos et al. conjectured that for all $k, m\geq 1$, the patterns $ 12\ldots k(k+m+1)\ldots (k+2)(k+1) $ and $(m+1)(m+2)\ldots (k+m+1)m\ldots 21 $ are $maj$-Wilf-equivalent.
Ge, Huiyun +2 more
core +4 more sources
Generating functions for Wilf equivalence under generalized factor order [PDF]
Kitaev, Liese, Remmel, and Sagan recently defined generalized factor order on words comprised of letters from a partially ordered set $(P, \leq_P)$ by setting $u \leq_P w$ if there is a subword $v$ of $w$ of the same length as $u$ such that the $i$-th ...
Langley, Thomas +2 more
core +4 more sources
Decreasing subsequences in permutations and Wilf equivalence for involutions [PDF]
In a recent paper, Backelin, West and Xin describe a map $\phi ^*$ that recursively replaces all occurrences of the pattern $k... 21$ in a permutation $\sigma$ by occurrences of the pattern $(k-1)... 21 k$.
Bousquet-Melou, Mireille +1 more
core +4 more sources
Radiometric Constraints on the Timing, Tempo, and Effects of Large Igneous Province Emplacement
Exploring the links between Large Igneous Provinces and dramatic environmental impact
An emerging consensus suggests that Large Igneous Provinces (LIPs) and Silicic LIPs (SLIPs) are a significant driver of dramatic global environmental and biological changes, including mass extinctions.
Jennifer Kasbohm +2 more
wiley +2 more sources
Bijections for generalized Wilf equivalences
Starting with an inclusion-exclusion proof of a combinatorial identity, a direct bijection can be produced using recursive subtraction (sometimes with a direct combinatorial description). We apply this method to identities for generalized Wilf equivalences among consecutive patterns in inversion sequences, giving direct bijective proofs of some ...
Melanie Ferreri
doaj +3 more sources
On (shape-)Wilf-equivalence for words [PDF]
AmS-LaTeX, 13 pages; minor ...
Guo, Ting +2 more
openaire +3 more sources
On refinements of wilf-equivalence for involutions
Let $\mathcal{S}_n(π)$ (resp. $\mathcal{I}_n(π)$ and $\mathcal{AI}_n(π)$) denote the set of permutations (resp. involutions and alternating involutions) of length $n$ which avoid the permutation pattern $π$. For $k,m\geq 1$, Backelin-West-Xin proved that $|\mathcal{S}_n(12\cdots kτ)|= |\mathcal{S}_n(k\cdots 21τ)|$ by establishing a bijection between ...
Sherry H. F. Yan +2 more
openaire +2 more sources
Two examples of unbalanced Wilf-equivalence [PDF]
10 pages, minor revision, to appear in Journal of ...
Burstein, Alexander, Pantone, Jay
openaire +2 more sources

