75 citations · 230 across the 32 of their papers we have counts for
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Two examples of Wilf-collapse
Michael Albert, Vít Jelínek, Michal Opler
Two permutation classes, the X-class and subpermutations of the increasing oscillation are shown to exhibit an exponential Wilf-collapse. This means that the number of distinct enu…
Wilf collapse in permutation classes
Michael Albert, Vít Jelínek, Michal Opler
For a hereditary permutation class , we say that two permutations and of are Wilf-equivalent in , if has the same numb…
Prolific Compositions
Murray Tannock, Michael Albert
Under what circumstances might every extension of a combinatorial structure contain more copies of another one than the original did? This property, which we call prolificity, hold…
Uniquely-Wilf classes
Michael Albert, Jinge Li
Two permutations in a class are Wilf-equivalent if, for every size, , the number of permutations in the class of size containing each of them is the same. Those infinite cla…
Embedding small digraphs and permutations in binary trees and split trees
Michael Albert, Cecilia Holmgren, Tony Johansson +1
We investigate the number of permutations that occur in random labellings of trees. This is a generalisation of the number of subpermutations occurring in a random permutation. It…