The wikipedia says that the number of nodes n in a full binary tree, is at least $n=2^h-1$ and at most $n=2^{h+1}-1$, where h is the height of the tree.
The following binary tree is full according to the wikipedia definition (every node has 0 or 2 children), n = 11, h = 4 but n is not greater than $2^4 - 1 = 15$.
Am I missing something?
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c d e f