Iranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X40420140801On the sum of Pell and Jacobsthal numbers by matrix method10171025548ENM.AkbulakSiirt UniversityA.ÖteleșDicle UniversityJournal Article20121130In this paper, we define two $n$-square upper Hessenberg matrices one of which corresponds to the adjacency matrix of a directed pseudo graph. We investigate relations between permanents and determinants of these upper Hessenberg matrices, and sum formulas of the well-known Pell and Jacobsthal sequences. Finally, we present two Maple 13 procedures in order to calculate permanents of these upper Hessenberg matrices.http://bims.iranjournals.ir/article_548_427451a378e7b360196f24cc5049fb08.pdf