eng
episciences.org
Discrete Mathematics & Theoretical Computer Science
1365-8050
2010-01-01
Vol. 12 no. 2
10.46298/dmtcs.496
496
journal article
The absence of a pattern and the occurrences of another
Miklós Bóna
Following a question of J. Cooper, we study the expected number of occurrences of a given permutation pattern q in permutations that avoid another given pattern r. In some cases, we find the pattern that occurs least often, (resp. most often) in all r-avoiding permutations. We also prove a few exact enumeration formulae, some of which are surprising.
https://dmtcs.episciences.org/496/pdf
Permutation pattern
generating functions
[INFO.INFO-DM] Computer Science [cs]/Discrete Mathematics [cs.DM]