English

A lower bound for the Wilf density, deduced from a result of Zhai

Number Theory 2021-08-10 v2

Abstract

Let SNS\neq\mathbb N be a numerical semigroup with Frobenius number ff, genus gg and embedding dimension ee. In 1978 Wilf asked the question, whether f+1gf+11e\frac{f+1-g}{f+1}\geq\frac1e. As is well known, this holds in the cases e=2e=2 and e=3e=3. From Zhai's results in [5] we derive f+1gf+12e2e+2 for e4.\frac{f+1-g}{f+1}\geq\frac2{e^2-e+2}\text{ for }e\geq4\,.

Keywords

Cite

@article{arxiv.2107.06752,
  title  = {A lower bound for the Wilf density, deduced from a result of Zhai},
  author = {Michael Hellus and Anton Rechenauer and Rolf Waldi},
  journal= {arXiv preprint arXiv:2107.06752},
  year   = {2021}
}

Comments

Stonger estimate with simpler proof, 3 pages