TwoProtectedNodeCount on OrderedTree
The number of vertices whose nearest leaf is exactly two edges away.
Called as CombinatorialStat(x, "TwoProtectedNodeCount"). The head's page has its examples.
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Distribution
Over OrderedTrees at each size, tallied here in your browser; sizes past 6 are not offered.
FindStat St000523
The number of 2-protected nodes of a rooted tree.
| Object | Value |
|---|---|
[[]] | 0 |
[[[]]] | 1 |
[[],[]] | 0 |
[[[[]]]] | 1 |
[[[],[]]] | 1 |
[[[]],[]] | 0 |
[[],[[]]] | 0 |
[[[[[]]]]] | 1 |
Data from FindStat, the combinatorial statistic finder; the page at findstat.org/St000523 has the rest.