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arXiv · 1909.03699

A graph-theoretic approach to Wilf's conjecture

Shalom Eliahou
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Abstract

Let S $\subseteq$ N be a numerical semigroup with multiplicity m = min(S \ {0}) and conductor c = max(N \ S) + 1. Let P be the set of primitive elements of S, and let L be the set of elements of S which are smaller than c. A longstand-ing open question by Wilf in 1978 asks whether the inequality |P||L| $\ge$ c always holds. Among many partial results, Wilf's conjecture has been shown to hold in case |P| $\ge$ m/2 by Sammartano in 2012. Using graph theory in an essential way, we extend the verification of Wilf's conjecture to the case |P| $\ge$ m/3. This case covers more than 99.999% of numerical semigroups of genus g $\le$ 45.

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Shalom Eliahou. 2019-09-09. A graph-theoretic approach to Wilf's conjecture. https://doi.org/10.37236/9106

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