A bijection between 2-triangulations and pairs of non-crossing Dyck paths

A k-triangulation of a convex polygon is a maximal set of diagonals so that no k + 1 of them mutually cross in their interiors. We present a bijection between 2-triangulations of a convex n-gon and pairs of non-crossing Dyck paths of length 2 ( n − 4 ) . This solves the problem of finding a bijective proof of a result of Jonsson for the case k = 2 . We obtain the bijection by constructing isomorphic generating trees for the sets of 2-triangulations and pairs of non-crossing Dyck paths.