2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/63540We characterize those sequences of weighted isobaric polynomials as defined in math.CO/0106213 which belong to the kernel of the linear operator $D_{11} - \sum_{j=1}^k a_j t_j D_{2j} - mD_2$, and we characterize those linear operators of this form in terms of the coefficients $a_j$ which have a non-zero kernel.11 pages, 2 figuresCombinatoricsAnalysis of PDEs05E05, 11B39, 47H60, 11N99text