2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/161607This note provide bijective proofs of two combinatorial identities involving generalized Catalan number $C_{m,5}(n)={m\over 5n+m}{5n+m\choose n}$ recently proposed by Sun.4 pagesCombinatorics05A15, 05A19text