Crucial and bicrucial permutations with respect to arithmetic monotone patterns
S. V. Avgustinovich, Sergey Kitaev, Alexandr Valyuzhenich · arXiv (Cornell University) · 2012
A pattern $τ$ is a permutation, and an arithmetic occurrence of $τ$ in (another) permutation $π=π_1π_2...π_n$ is a subsequence $π_{i_1}π_{i_2}...π_{i_m}$ of $π$ that is order isomorphic to $τ$ where the numbers $i_1