English

On two-term hypergeometric recursions with free lower parameters

Classical Analysis and ODEs 2024-03-27 v2

Abstract

Let F(n,k)F(n,k) be a hypergeometric function that may be expressed so that nn appears within initial arguments of inverted Pochhammer symbols, as in factors of the form 1(n)k\frac{1}{(n)_{k}}. Only in exceptional cases is F(n,k)F(n, k) such that Zeilberger's algorithm produces a two-term recursion for k=0F(n,k)\sum_{k = 0}^{\infty} F(n, k) obtained via the telescoping of the right-hand side of a difference equation of the form p1(n)F(n+r,k)+p2(n)F(n,k)=G(n,k+1)G(n,k)p_{1}(n) F(n + r, k) + p_{2}(n) F(n, k) = G(n, k+1) - G(n, k) for fixed rNr \in \mathbb{N} and polynomials p1p_{1} and p2p_{2}. Building on the work of Wilf, we apply a series acceleration technique based on two-term hypergeometric recursions derived via Zeilberger's algorithm. Fast converging series previously given by Ramanujan, Guillera, Chu and Zhang, Chu, Lupa\c{s}, and Amdeberhan are special cases of hypergeometric transforms introduced in our article.

Keywords

Cite

@article{arxiv.2305.00626,
  title  = {On two-term hypergeometric recursions with free lower parameters},
  author = {John M. Campbell and Paul Levrie},
  journal= {arXiv preprint arXiv:2305.00626},
  year   = {2024}
}

Comments

Accepted for publication in the Journal of Difference Equations and Applications

R2 v1 2026-06-28T10:22:10.512Z