The pattern-avoidance inequalities conjecture for restricted-cycle permutations

For each n1n\geq 1, let an{1,3}(σ)a_n^{\{1,3\}}(\sigma) count length-nn permutations avoiding the pattern σ\sigma whose cycle lengths belong to {1,3}\{1,3\}, and let an{1,2,3}(σ)a_n^{\{1,2,3\}}(\sigma) count length-nn permutations avoiding σ\sigma whose cycle lengths belong to {1,2,3}\{1,2,3\}. Pattern-avoidance inequalities conjecture. For n1n\geq 1, one has

an{1,3}(132)an{1,3}(321)a_n^{\{1,3\}}(132) \leq a_n^{\{1,3\}}(321)

and

an{1,2,3}(123)an{1,2,3}(132)an{1,2,3}(321)an{1,2,3}(231).a_n^{\{1,2,3\}}(123) \leq a_n^{\{1,2,3\}}(132)\leq a_n^{\{1,2,3\}}(321)\leq a_n^{\{1,2,3\}}(231).

These inequalities are conjectured from numerical evidence in the cited tables; the supplied text does not establish them or report a resolution.

Sources & referencesView supporting material

Primary source

Kassie Archer and Robert P. Laudone, “Pattern-restricted permutations of small order”, arXiv:2402.15463 (2024).

Progress summary

Never refreshed

Nothing recorded yet. Refresh searches the literature and the public web for attempts on this problem, and writes the first summary here.

Solutions 0

No solutions have been posted yet.