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KrattenthalerPermutation ​

The 321-avoiding permutation whose left-to-right maxima are the path's peaks: Krattenthaler's bijection.

KrattenthalerPermutation(DyckPath)The 321-avoiding permutation whose left-to-right maxima are the path's peaks: Krattenthaler's bijection.
Typed signatures
TypePackageApplies
(dyck_path) -> permutationcombinatoricsalways

Domain: Combinatorial maps

Details
  • Takes a DyckPath and returns a Permutation — a typed map, so a wrong carrier is a type error rather than a wrong answer.
  • FindStat's Mp00119. The value at a peak is the ups so far and its position the downs so far plus one; the other values fill the other positions increasingly. The first step of KnuthKrattenthaler.

Examples

Basic #

the Dyck path UUDDUDUUDDUD

live ↗
InKrattenthalerPermutation(DyckPath⁡([1,1,0,0,1,0]))\mathrm{KrattenthalerPermutation}({\operatorname{DyckPath}}([1, 1, 0, 0, 1, 0]))OutPermutation⁡([2,1,3]){\operatorname{Permutation}}([2, 1, 3])
About
Examples1
CrosswalkFindStat