# Fungrim entry: 2443de

$R_{-a}\!\left(\left[b_{1}, b_{2}, \ldots, b_{n}\right], \left[z_{1}, z_{2}, \ldots, z_{n}\right]\right) = z_{n}^{-a} \sum_{N=0}^{\infty} \frac{\left(a\right)_{N}}{\left(c\right)_{N}} T_{N}\!\left(\left[b_{1}, b_{2}, \ldots, b_{n - 1}\right], \left[1 - \frac{z_{1}}{z_{n}}, 1 - \frac{z_{2}}{z_{n}}, \ldots, 1 - \frac{z_{n - 1}}{z_{n}}\right]\right)\; \text{ where } c = \sum_{k=1}^{n} b_{k}$
Assumptions:$a \in \mathbb{R} \;\mathbin{\operatorname{and}}\; n \in \mathbb{Z}_{\ge 1} \;\mathbin{\operatorname{and}}\; \left(b_{k} \in \mathbb{R} \;\text{ for all } k \in \{1, 2, \ldots, n\}\right) \;\mathbin{\operatorname{and}}\; z_{n} \in \mathbb{C} \setminus \left\{0\right\} \;\mathbin{\operatorname{and}}\; \left(z_{k} \in \mathbb{C} \;\mathbin{\operatorname{and}}\; \left|1 - \frac{z_{k}}{z_{n}}\right| < 1 \;\text{ for all } k \in \{1, 2, \ldots, n - 1\}\right) \;\mathbin{\operatorname{and}}\; \sum_{k=1}^{n} b_{k} > 0 \;\mathbin{\operatorname{and}}\; \left(\operatorname{Re}\!\left(z_{k}\right) > 0 \;\text{ for all } k \in \{1, 2, \ldots, n\}\right)$
TeX:
R_{-a}\!\left(\left[b_{1}, b_{2}, \ldots, b_{n}\right], \left[z_{1}, z_{2}, \ldots, z_{n}\right]\right) = z_{n}^{-a} \sum_{N=0}^{\infty} \frac{\left(a\right)_{N}}{\left(c\right)_{N}} T_{N}\!\left(\left[b_{1}, b_{2}, \ldots, b_{n - 1}\right], \left[1 - \frac{z_{1}}{z_{n}}, 1 - \frac{z_{2}}{z_{n}}, \ldots, 1 - \frac{z_{n - 1}}{z_{n}}\right]\right)\; \text{ where } c = \sum_{k=1}^{n} b_{k}

a \in \mathbb{R} \;\mathbin{\operatorname{and}}\; n \in \mathbb{Z}_{\ge 1} \;\mathbin{\operatorname{and}}\; \left(b_{k} \in \mathbb{R} \;\text{ for all } k \in \{1, 2, \ldots, n\}\right) \;\mathbin{\operatorname{and}}\; z_{n} \in \mathbb{C} \setminus \left\{0\right\} \;\mathbin{\operatorname{and}}\; \left(z_{k} \in \mathbb{C} \;\mathbin{\operatorname{and}}\; \left|1 - \frac{z_{k}}{z_{n}}\right| < 1 \;\text{ for all } k \in \{1, 2, \ldots, n - 1\}\right) \;\mathbin{\operatorname{and}}\; \sum_{k=1}^{n} b_{k} > 0 \;\mathbin{\operatorname{and}}\; \left(\operatorname{Re}\!\left(z_{k}\right) > 0 \;\text{ for all } k \in \{1, 2, \ldots, n\}\right)
Definitions:
Fungrim symbol Notation Short description
CarlsonHypergeometricR$R_{-a}\!\left(b, z\right)$ Carlson multivariate hypergeometric function
Pow${a}^{b}$ Power
Sum$\sum_{n} f(n)$ Sum
RisingFactorial$\left(z\right)_{k}$ Rising factorial
CarlsonHypergeometricT$T_{N}\!\left(b, z\right)$ Term in expansion of Carlson multivariate hypergeometric function
Infinity$\infty$ Positive infinity
RR$\mathbb{R}$ Real numbers
ZZGreaterEqual$\mathbb{Z}_{\ge n}$ Integers greater than or equal to n
Range$\{a, a + 1, \ldots, b\}$ Integers between given endpoints
CC$\mathbb{C}$ Complex numbers
Abs$\left|z\right|$ Absolute value
Re$\operatorname{Re}(z)$ Real part
Source code for this entry:
Entry(ID("2443de"),
Formula(Where(Equal(CarlsonHypergeometricR(Neg(a), List(b_(k), For(k, 1, n)), List(z_(k), For(k, 1, n))), Mul(Pow(z_(n), Neg(a)), Sum(Mul(Div(RisingFactorial(a, N), RisingFactorial(c, N)), CarlsonHypergeometricT(N, List(b_(k), For(k, 1, Sub(n, 1))), List(Sub(1, Div(z_(k), z_(n))), For(k, 1, Sub(n, 1))))), For(N, 0, Infinity)))), Def(c, Sum(b_(k), For(k, 1, n))))),
Variables(a, b_, z_, n),
Assumptions(And(Element(a, RR), Element(n, ZZGreaterEqual(1)), All(Element(b_(k), RR), ForElement(k, Range(1, n))), Element(z_(n), SetMinus(CC, Set(0))), All(And(Element(z_(k), CC), Less(Abs(Sub(1, Div(z_(k), z_(n)))), 1)), ForElement(k, Range(1, Sub(n, 1)))), Greater(Sum(b_(k), For(k, 1, n)), 0), All(Greater(Re(z_(k)), 0), ForElement(k, Range(1, n))))))

## Topics using this entry

Copyright (C) Fredrik Johansson and contributors. Fungrim is provided under the MIT license. The source code is on GitHub.

2021-03-15 19:12:00.328586 UTC