English

Pseudo-factorials, elliptic functions, and continued fractions

Classical Analysis and ODEs 2009-05-31 v2 Combinatorics Number Theory

Abstract

This study presents miscellaneous properties of pseudo-factorials, which are numbers whose recurrence relation is a twisted form of that of usual factorials. These numbers are associated with special elliptic functions, most notably, a Dixonian and a Weierstrass function, which parametrize the Fermat cubic curve and are relative to a hexagonal lattice. A continued fraction expansion of the ordinary generating function of pseudo-factorials, first discovered empirically, is established here. This article also provides a characterization of the associated orthogonal polynomials, which appear to form a new family of "elliptic polynomials", as well as various other properties of pseudo-factorials, including a hexagonal lattice sum expression and elementary congruences.

Keywords

Cite

@article{arxiv.0901.1379,
  title  = {Pseudo-factorials, elliptic functions, and continued fractions},
  author = {Roland Bacher and Philippe Flajolet},
  journal= {arXiv preprint arXiv:0901.1379},
  year   = {2009}
}

Comments

24 pages; with correction of typos and minor revision. To appear in The Ramanujan Journal

R2 v1 2026-06-21T11:59:24.489Z