073607ba-7ec7-414d-a715-4985e4d6d91220211228064001395naun:naunmdt@crossref.orgMDT DepositInternational Journal of Pure Mathematics2313-057110.46300/91019http://www.naun.org/cms.action?id=6985292021292021810.46300/91019.2021.8https://www.naun.org/cms.action?id=23293Integer Programming Formulations For The Frobenius ProblemImdatKaraDepartment of Industrial Engineering, Department of Finance and Banking Baskent University Baglica Campus, 06790, Etimesgut, Ankara, Turkey TurkeyHalil IbrahimKarakasDepartment of Industrial Engineering, Department of Finance and Banking Baskent University Baglica Campus, 06790, Etimesgut, Ankara, Turkey TurkeyThe Frobenius number of a set of relatively prime positive integers α1,α2,…,αn such that α1< α2< …< αn, is the largest integer that can not be written as a nonnegative integer linear combination of the given set. Finding the Frobenius number is known as the Frobenius problem, which is also named as the coin exchange problem or the postage stamp problem. This problem is closely related with the equality constrained integer knapsack problem. It is known that this problem is NP-hard. Extensive research has been conducted for finding the Frobenius number of a given set of positive integers. An exact formula exists for the case n=2 and various formulas have been derived for all special cases of n = 3. Many algorithms have been proposed for n≥4. As far as we are aware, there does not exist any integer programming approach for this problem which is the main motivation of this paper. We present four integer linear programming formulations about the Frobenius number of a given set of positive integers. Our first formulation is used to check if a given positive integer is the Frobenius number of a given set of positive integers. The second formulation aims at finding the Frobenius number directly. 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