OpenerBeforeCloserPairs on SetPartition
Pairs a < b in different blocks with a the least and b the greatest element of its block.
Called as CombinatorialStat(x, "OpenerBeforeCloserPairs"). The head's page has its examples.
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Distribution
Over SetPartitions at each size, tallied here in your browser; sizes past 10 are not offered.
FindStat St000574
The number of occurrences of the pattern {{1},{2}} such that 1 is a minimal and 2 a maximal element.
| Object | Value |
|---|---|
{{1,2}} | 0 |
{{1,2,3}} | 0 |
{{1},{2}} | 1 |
{{1,2,3,4}} | 0 |
{{1,2},{3}} | 1 |
{{1,3},{2}} | 2 |
{{1},{2,3}} | 1 |
{{1,2,3,4,5}} | 0 |
Data from FindStat, the combinatorial statistic finder; the page at findstat.org/St000574 has the rest.