2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/213918We solve the center problem for ODEs \frac{dv}{dx}=\sum_{i=1}^{\infty}a_{i}(x) v^{i+1} such that the first integrals of vectors of their coefficients determine rectangular paths in finite dimensional complex vector spaces.8 pagesClassical Analysis and ODEsComplex Variables37L10, 34C07text