@UNPUBLISHED{publication1, title = "Discrete semi-classical orthogonal polynomials of class one on quadratic lattices", author = "{FILIPUK, Galina} and {REBOCHO, Maria das Neves}", year = "2018-11-07", abstract = "We study orthogonal polynomials on quadratic lattices with respect to a Stieltjes function, S, that satisfies a difference equation ADS = CMS+D, where A is a polynomial of degree less or equal than 3 and C is a polynomial of degree greater or equal than 1 and less or equal than 2. We show systems of difference equations for the orthogonal polynomials that arise from the so-called compatibility conditions. Some closed formulae for the recurrence relation coefficients are obtained. ", url = "http://www.mat.uc.pt/preprints/eng\_2018.html", note = "" }