Gets the second merge column. Merge2[n] holds the index representing the second cluster/leaf to join at level n. Merge1 and Merge2 hold information about which clusters are joined and in what order they are joined. Negative values refer to leaves (1-based indexing of the input), positive values refer to clusters joined at lower level (1-based indexing of merge1 and merge2).

Observe that PageableList indexing is zero-base but the information in Merge1 and Merge2 is 1-based.

public PageableList<int> Merge2 { get; }