# Convergence of ray sequences of Pade approximants to 2F1(a,1;c;z), c\>a\>0

Source: [Convergence of ray sequences of Pade approximants to 2F1(a,1;c;z), c\>a\>0](<https://www.sota2.com/research/paper/68fa4e121e209131ce95925d>)

Collection index: [llms.txt](<https://www.sota2.com/research/llms.txt>)

Data updated: 2025-10-28T13:55:10.627Z

Authors: K Driver, K Jordaan

Published: 2009-01-05T08:49:35.000Z

## Abstract

The Pad\\'e table of $\\phantom{}\_2F\_1(a,1;c;z)$ is normal for $c\>a\>0$ (cf. \\cite{3}). For $m \\geq n-1$ and $c \\notin {\\zz}^{\\phantom{}^-}$, the denominator polynomial $Q\_{mn}(z)$ in the $\[m/n\]$ Pad\\'e approximant $P\_{mn}(z)/Q\_{mn}(z)$ for $\\phantom{}\_2F\_1(a,1;c;z)$ and the remainder term $Q\_{mn}(z)\\phantom{}\_2F\_1(a,1;c;z)-P\_{mn}(z)$ were explicitly evaluated by Pad\\'e (cf. \\cite{2}, \\cite{5} or \\cite{7}). We show that for $c\>a\>0$ and $m\\geq n-1$, the poles of $P\_{mn}(z)/Q\_{mn}(z)$ lie on the cut $(1,\\infty)$. We deduce that the sequence of approximants $P\_{mn}(z)/Q\_{mn}(z)$ converges to $\\phantom{}\_2F\_1(a,1;c;z)$ as $m \\to \\infty$, $ n/m \\to \\rho$ with $0\<\\rho \\leq 1$, uniformly on compact subsets of the unit disc $\|z\|\<1$ for $c\>a\>0$

## Recorded benchmark results

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## Original sources and implementation

[Original paper](<https://arxiv.org/abs/0901.0435>)

[PDF](<https://arxiv.org/pdf/0901.0435.pdf>)
