  In the context of connections between algebras coming from quantum integrable
systems and algebras associated to the orthogonal polynomials of the Askey
scheme, we prove that the truncated reflection algebra attached to the Yangian
of sl(2) is isomorphic to the Hahn algebra. As a by-product, we provide a
general set-up based on Euler polynomials to study truncations of reflection
algebras.
