2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/56725We propose a new analytical method to solve for nonexactly soluble Schrodinger equation via expansions through some existing quantum numbers. Successfully, it is applied to the rational non-polynomial oscillator potential. Moreover, a conclusion reached by Scherrer et al. [2], via matrix continued fractions method, that the shifted large N expansion method leads to dubious accuracies is investigated. The cutoff - Coulomb and Coulomb plus logarithmic potentials are also investigated.Conference on Analysis and Mathematical Physics, Lund University, Lund - Sweden, August 16-20,1999, text of 30 mnts talk for proceedingsMathematical Physicstext