Existence of 3-inflatable permutations in every admissible residue class modulo 144
Existence of 3-inflatable permutations in every admissible residue class modulo 144
A permutation is 3-inflatable if its pattern densities of length satisfy the prescribed inflation criterion. The admissible residue classes modulo are the residue classes identified by the necessary conditions for the existence of such permutations.
Existence conjecture. For every positive integer whose length belongs to an admissible residue class modulo , there exists a 3-inflatable permutation of length .
The conjecture is motivated by computer searches that found centrally symmetric 3-inflatable permutations of lengths , , , , , and , as well as examples in every admissible residue class modulo .
Progress summary
Nothing recorded yet. Refresh searches the literature and the public web for attempts on this problem, and writes the first summary here.
Sources & referencesView supporting material
Primary source
Tanya Khovanova and Eric Zhang, “Limit Densities of Patterns in Permutation Inflations”, arXiv:1809.08490 (2021).
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