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Hag on Permutation ​

The excedance tops less their positions, plus the inversions among the excedance tops less those among the rest, plus the pairs k < i, over excedances i, with p(k) <= i.

On Permutation

FindStat's Haglund hag. The inversions are within the subwords, as in Denert.

Called as CombinatorialStat(x, "Hag"). The head's page has its examples.

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Distribution

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FindStat St001671

Haglund's hag of a permutation.

ObjectValue
[1]0
[1,2]0
[2,1]1
[1,2,3]0
[1,3,2]2
[2,1,3]1
[2,3,1]3
[3,1,2]2

Data from FindStat, the combinatorial statistic finder; the page at findstat.org/St001671 has the rest.