Fungrim home page

Fungrim entry: dfb55b

ψ(m) ⁣(z)=(1)m+1m!n=01(n+z)m+1\psi^{(m)}\!\left(z\right) = {\left(-1\right)}^{m + 1} m ! \sum_{n=0}^{\infty} \frac{1}{{\left(n + z\right)}^{m + 1}}
Assumptions:mZ1  and  zC  and  z{0,1,}m \in \mathbb{Z}_{\ge 1} \;\mathbin{\operatorname{and}}\; z \in \mathbb{C} \;\mathbin{\operatorname{and}}\; z \notin \{0, -1, \ldots\}
TeX:
\psi^{(m)}\!\left(z\right) = {\left(-1\right)}^{m + 1} m ! \sum_{n=0}^{\infty} \frac{1}{{\left(n + z\right)}^{m + 1}}

m \in \mathbb{Z}_{\ge 1} \;\mathbin{\operatorname{and}}\; z \in \mathbb{C} \;\mathbin{\operatorname{and}}\; z \notin \{0, -1, \ldots\}
Definitions:
Fungrim symbol Notation Short description
DigammaFunctionψ ⁣(z)\psi\!\left(z\right) Digamma function
Powab{a}^{b} Power
Factorialn!n ! Factorial
Sumnf(n)\sum_{n} f(n) Sum
Infinity\infty Positive infinity
ZZGreaterEqualZn\mathbb{Z}_{\ge n} Integers greater than or equal to n
CCC\mathbb{C} Complex numbers
ZZLessEqualZn\mathbb{Z}_{\le n} Integers less than or equal to n
Source code for this entry:
Entry(ID("dfb55b"),
    Formula(Equal(DigammaFunction(z, m), Mul(Mul(Pow(-1, Add(m, 1)), Factorial(m)), Sum(Div(1, Pow(Add(n, z), Add(m, 1))), For(n, 0, Infinity))))),
    Variables(m, z),
    Assumptions(And(Element(m, ZZGreaterEqual(1)), Element(z, CC), NotElement(z, ZZLessEqual(0)))))

Topics using this entry

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

2020-08-27 09:56:25.682319 UTC