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FoataInversionsToMajor from Permutation ​

The inverse of Foata's major-to-inversions bijection: peel off the last letter, rotate the blocks of the rest back.

Permutation → Permutationbijectioninverse

FindStat's Mp00175, Sage's foata_bijection_inverse. It sends the number of inversions to the major index.

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

Live

Explore

Each element of Permutation at a size, and its image, applied in your browser; sizes past 7 are not offered.

Properties

Transport a statistic

Pick a statistic on Permutation. Its distribution over the images of Permutation at each size is computed, and compared with the 323 statistics on Permutation: those that share it are the ones the map sends it to, as far as the sizes computed show.

Also from

The same name out of other carriers, each its own implementation: IntegerComposition, BinaryWord.

FindStat Mp00175

inverse Foata bijection

Matched by value: our map agrees with FindStat's image on each of the 873 rows of size at most 6 we can read (0 unread; its table has 1200 rows).

BijectionGraded mapas FindStat records them, checked by FindStat's contributors.

The inverse of Foata's bijection.
ObjectImage
[1][1]
[1,2][1,2]
[2,1][2,1]
[1,2,3][1,2,3]

Data from FindStat, the combinatorial statistic finder; the page at findstat.org/Mp00175 has the rest.