LalanneKreweras from DyckPath
The Lalanne-Kreweras involution: labels of the ups and downs that start a double rise or fall, differenced.
An involution that swaps the number of peaks with the number of double rises, and area-related statistics with their dual. Mp00120.
Called as CombinatorialMap(x, "LalanneKreweras"). The head's page has its examples.
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Properties
Transport a statistic
Pick a statistic on DyckPath. Its distribution over the images of DyckPath at each size is computed, and compared with the 171 statistics on DyckPath: those that share it are the ones the map sends it to, as far as the sizes computed show.
FindStat Mp00120
Lalanne-Kreweras involution
Matched by value: our map agrees with FindStat's image on each of the 196 rows of size at most 6 we can read (0 unread; its table has 1200 rows).
BijectionGraded mapInvolutionas FindStat records them, checked by FindStat's contributors.
| Object | Image |
|---|---|
[1,0] | [1,0] |
[1,0,1,0] | [1,1,0,0] |
[1,1,0,0] | [1,0,1,0] |
[1,0,1,0,1,0] | [1,1,1,0,0,0] |
Data from FindStat, the combinatorial statistic finder; the page at findstat.org/Mp00120 has the rest.