English

Bounds for invariants of numerical semigroups and Wilf's Conjecture

Number Theory 2022-08-31 v1 Combinatorics

Abstract

Given coprime positive integers g1<<geg_1 < \ldots < g_e, the Frobenius number F=F(g1,,ge)F=F(g_1,\ldots,g_e) is the largest integer not representable as a linear combination of g1,,geg_1,\ldots,g_e with non-negative integer coefficients. Let nn denote the number of all representable non-negative integers less than FF; Wilf conjectured that F+1enF+1 \le e n. We provide bounds for g1g_1 and for the type of the numerical semigroup S=g1,,geS=\langle g_1,\ldots,g_e \rangle in function of ee and nn, and use these bounds to prove that F+1qenF+1 \le q e n, where q=F+1g1q= \left \lceil \frac{F+1}{g_1} \right \rceil, and F+1en2F+1 \le e n^2. Finally, we give an alternative, simpler proof for the Wilf conjecture if the numerical semigroup S=g1,,geS=\langle g_1,\ldots,g_e \rangle is almost-symmetric.

Keywords

Cite

@article{arxiv.2208.14090,
  title  = {Bounds for invariants of numerical semigroups and Wilf's Conjecture},
  author = {Marco D'Anna and Alessio Moscariello},
  journal= {arXiv preprint arXiv:2208.14090},
  year   = {2022}
}

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6 pages