DescentDifferenceSum on Permutation
The sum of p(i) - p(i+1) over the descents i.
Also called the drop of a permutation.
Called as CombinatorialStat(x, "DescentDifferenceSum"). The head's page has its examples.
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FindStat St000030
The sum of the descent differences of a permutations.
| Object | Value |
|---|---|
[1] | 0 |
[1,2] | 0 |
[2,1] | 1 |
[1,2,3] | 0 |
[1,3,2] | 1 |
[2,1,3] | 1 |
[2,3,1] | 2 |
[3,1,2] | 2 |
Data from FindStat, the combinatorial statistic finder; the page at findstat.org/St000030 has the rest.