Rooted plane tree
= Rooted plane tree
A <plane tree> with a distinguished root and root corner, equivalently a <rooted tree> with a linear order on the children at each vertex. Trees with $n$ edges are counted by the <Catalan number> $C_n$.
= Rooted plane tree
A <plane tree> with a distinguished root and root corner, equivalently a <rooted tree> with a linear order on the children at each vertex. Trees with $n$ edges are counted by the <Catalan number> $C_n$.