2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/58532We prove an identity about partitions, previously conjectured in the study of shifted Jack polynomials (math.CO/9903020). The proof given is using $λ$-ring techniques. It would be interesting to obtain a bijective proof.16 pages, LaTeX, in FrenchCombinatoricstext