Pochhammer[a,n]
gives the Pochhammer symbol
.
Pochhammer
Pochhammer[a,n]
gives the Pochhammer symbol
.
Details
- Mathematical function, suitable for both symbolic and numerical manipulation.
. - For certain special arguments, Pochhammer automatically evaluates to exact values.
- Pochhammer can be evaluated to arbitrary numerical precision.
- Pochhammer automatically threads over lists.
- Pochhammer can be used with Interval and CenteredInterval objects. »
Examples
open all close allBasic Examples (7)
Pochhammer[10, 6]Evaluate symbolically with respect to n:
Pochhammer[n, 5]Pochhammer[n, -5]Plot over a subset of the reals:
Plot[Pochhammer[x, 1 / 2], {x, -.5, 4}]Plot over a subset of the complexes:
ComplexPlot3D[Pochhammer[z, 2], {z, -2 - 2I, 2 + 2I}, PlotLegends -> Automatic]Series expansion at the origin:
Series[Pochhammer[x, 1 / 2], {x, 0, 2}]//FullSimplifySeries expansion at Infinity:
Series[Pochhammer[x, 1 / 2], {x, ∞, 3}]//FullSimplifySeries expansion at a singular point:
Series[Pochhammer[x, -3], {x, 1, 3}]Scope (36)
Numerical Evaluation (7)
Pochhammer[2.4, 8.5]Pochhammer[0, 1285]Evaluate for half‐integer arguments:
Pochhammer[3 / 2, 1 / 2]N[Pochhammer[1 / 3, 7], 50]The precision of the output tracks the precision of the input:
Pochhammer[1.011111111111000000000000000, 8]Pochhammer[2. + 5 I, 8 I]Evaluate efficiently at high precision:
Pochhammer[4 / 8`100, 8]//TimingPochhammer[48, 94`1000000];//TimingCompute worst-case guaranteed intervals using Interval and CenteredInterval objects:
Pochhammer[Interval[{1.23, 1.24}], Interval[{2.34, 2.35}]]Pochhammer[CenteredInterval[2, 1 / 100], CenteredInterval[3, 1 / 100]]Pochhammer[CenteredInterval[5 + 3I, (1 + I) / 1000], 3 / 5]Or compute average-case statistical intervals using Around:
Pochhammer[Around[2, 0.01], 2]Compute the elementwise values of an array:
Pochhammer[ {{5π / 6, 0}, {3π / 2, -π / 2}}, 2]Or compute the matrix Pochhammer function using MatrixFunction:
MatrixFunction[Pochhammer[#, 2]&, {{5π / 6, 0}, {3π / 2, -π / 2}}]Specific Values (6)
Values of Pochhammer at fixed points:
Table[Pochhammer[x, 2], {x, 1, 5}]Obtain the polynomial representation Pochhammer[x,n] for integer values of n:
Pochhammer[x, 4]Expand Pochhammer[x,n] for a fixed value of x:
Pochhammer[(3/2), n]//FunctionExpandPochhammer[0, 1]Infinite arguments give symbolic results:
Pochhammer[Infinity, 2]Find a value of x for which Pochhammer[x,2]=15:
xval = x /. FindRoot[Pochhammer[ x , 2] == 15, {x, 3}]Plot[Pochhammer[x, 2], {x, 0, 5}, Epilog -> Style[Point[{xval, Pochhammer[xval, 2]}], PointSize[Large], Red]]Visualization (3)
Plot the Pochhammer function for various orders:
Plot[{Pochhammer[x, 1], Pochhammer[x, 2], Pochhammer[x, 3], Pochhammer[x, 4]}, {x, -4, 4}]Plot Pochhammer as a function of its parameter
:
Plot[{Pochhammer[1, n], Pochhammer[2, n], Pochhammer[3, n], Pochhammer[4, n]}, {n, 0, 4}]ComplexContourPlot[Re[Pochhammer[z, 5]], {z, -1 - 2I, 1 + 2I}, Contours -> 20]ComplexContourPlot[Im[Pochhammer[z, 5]], {z, -1 - 2I, 1 + 2I}, Contours -> 20]Function Properties (11)
Real domain of Pochhammer:
FunctionDomain[Pochhammer[x, y], {x, y}]FunctionDomain[Pochhammer[z, w], {z, w}, Complexes]Function range of Pochhammer[x,n] for various fixed values of n:
Table[FunctionRange[Pochhammer[x, n], x, y], {n, {0, 1 / 2, 1, 2}}]Pochhammer has the mirror property
:
FullSimplify[Pochhammer[Conjugate[z], 2] == Conjugate[Pochhammer[z, 2]]]FunctionAnalytic[Pochhammer[x, 3], x]
is neither non-decreasing nor non-increasing:
FunctionMonotonicity[Pochhammer[x, 3], x]FunctionInjective[Pochhammer[x, 3], x]Plot[{Pochhammer[x, 3], .2}, {x, -2, 2}]FunctionSurjective[Pochhammer[x, 3], x]Plot[{Pochhammer[x, 3], 10}, {x, -5, 5}]
is neither non-negative nor non-positive:
FunctionSign[Pochhammer[x, 3], x]
does not have either singularity or discontinuity:
FunctionSingularities[Pochhammer[x, 3], x]
is neither convex nor concave:
FunctionConvexity[Pochhammer[x, 3], x]TraditionalForm formatting:
Pochhammer[n, k]//TraditionalFormDifferentiation (2)
First derivative of
with respect to
:
D[Pochhammer[a, n], a]First derivative of
with respect to
:
D[Pochhammer[a, n], n]Higher derivatives of
with respect to
:
Table[D[Pochhammer[a, n], {a, k}], {k, 1, 3}]//FullSimplifyPlot the higher derivatives with respect to a when n=5:
Plot[Evaluate[% /. {n -> 5}], {a, -1 / 2, 1 / 2}, PlotLegends -> {"First Derivative", "Second Derivative", "Third Derivative"}]Series Expansions (5)
Find the Taylor expansion using Series:
Series[Pochhammer[a, n], {n, 0, 3}]//NormalPlots of the first three approximations around
:
funcAndSeries = Prepend[Table[Series[Pochhammer[2, n], {n, 0, m}], {m, 1, 5, 2}], Pochhammer[2, n]]//Normal;
Plot[funcAndSeries, {n, 0, 10}, PlotRange -> {0, 50}]Find a series expansion at Infinity:
Series[Pochhammer[a, n], {a, Infinity, 2}]//NormalFind a series expansion for an arbitrary symbolic direction
:
Series[Pochhammer[a, n], {n, DirectedInfinity[z], 1}, Assumptions -> n > 0]// FullSimplifyTaylor expansion at a generic point:
Series[Pochhammer[n, x], {x, x0, 2}]// Normal//FullSimplifyPochhammer can be applied to a power series:
Pochhammer[(1 + x + O[x]^5), 10]Function Identities and Simplifications (2)
Pochhammer[a, n] == Pochhammer[a, m] Pochhammer[a + m, n - m]//FullSimplifyPochhammer[a, n] == (a + n - 1/a - 1) Pochhammer[a - 1, n]//FullSimplifyPochhammer[a, n] == (a/a + n) Pochhammer[a + 1, n]//FullSimplifyApplications (4)
Obtain elementary and special functions from infinite sums:
Sum[Pochhammer[a, k] z ^ k / k!, {k, 0, Infinity}]Sum[1 / Pochhammer[b, k] z ^ k / k!, {k, 0, Infinity}]Sum[Pochhammer[a, -k]Pochhammer[b, -k]z ^ k / k!, {k, 0, Infinity}]Plot Pochhammer for various values of a parameter:
Plot[Evaluate[Table[Pochhammer[x, k], {k, 0, 4}]], {x, -6, 6}]Plot[Evaluate[Table[Pochhammer[k, x], {k, 0, 4}]], {x, -6, 2}]The average number of runs of length
or larger in a sequence of zeros and ones:
av[zeros_, ones_, r_] := ((1 + zeros)Pochhammer[-ones, r] + (1 + ones)Pochhammer[-zeros, r]) / Pochhammer[-ones - zeros, r]Count runs in a random binary sequence:
data = RandomInteger[{0, 1}, 1000000];Count[Split[data], _ ? (Length[#] ≥ 3&)]Compare with the theoretical average:
av[Count[data, 0], Count[data, 1], 3]//NDefine a negative hypergeometric distribution:
NegativeHypergeometricDistribution[w_, wtot_, btot_] := BetaBinomialDistribution[w, wtot - w + 1, btot]Find the probability that
black balls were sampled without replacement before a ![]()
white ball was drawn from an urn initially filled with
black and
white balls:
Probability[x == b, xNegativeHypergeometricDistribution[w, Subscript[k, w], Subscript[k, b]]]Alternatively, compute the probability of drawing a white ball provided that there were
black balls in the previous
samplings without replacement:
FullSimplify[% == Probability[y == b, yHypergeometricDistribution[w + b - 1, Subscript[k, b], Subscript[k, w] + Subscript[k, b]]]((Subscript[k, w] - w + 1)/Subscript[k, w] + Subscript[k, b] - w - b + 1), 0 < w < Subscript[k, w] && 0 < b < Subscript[k, b] && (w | b | Subscript[k, w] | Subscript[k, b])∈Integers]Properties & Relations (10)
Use FullSimplify to simplify expressions involving Pochhammer:
FullSimplify[Gamma[a]Pochhammer[a, k]]Use FunctionExpand to expand in Pochhammer in terms of Gamma functions:
FunctionExpand[Pochhammer[n, k]]Pochhammer can be expressed in terms of a single FactorialPower expression:
Pochhammer[a, n] == FactorialPower[a + n - 1, n]//FullSimplifyVerify the identity
for integer
:
FullSimplify[Pochhammer[a, n] == FactorialPower[a, n, -1]//FunctionExpand, n∈ℤ]Verify an expansion of Pochhammer in terms of FactorialPower for the first few cases:
Table[Pochhammer[a, n] == Underoverscript[∑, k = 0, n](n!/k!)Binomial[n - 1, k - 1]FactorialPower[a, k]//FunctionExpand//Simplify, {n, 0, 9}]Sums involving Pochhammer:
Underoverscript[∑, k = 0, n]Pochhammer[n, k] x ^ kUnderoverscript[∑, k = 1, ∞]1 / Pochhammer[n, k] ^ 2z^kUnderoverscript[∑, k = 1, ∞](1/Pochhammer[2 k, k])RSolve[n p[n] == p[n + 1], p, n]The generating function is divergent:
Underoverscript[∑, k = 0, ∞]Pochhammer[n, k] x ^ kSum[Pochhammer[n, k] x ^ k, {k, 0, Infinity}, Regularization -> "Borel"]Consider the generating function as a formal power series:
Series[-Exp[-1 / x] / x ExpIntegralE[n, -1 / x], {x, 0, 4}]Collect[Sum[Pochhammer[n, k] x ^ k, {k, 0, 4}], x, Expand]Series[HypergeometricPFQ[{n, 1}, {}, x], {x, 0, 4}]Pochhammer can be represented as a DifferenceRoot:
DifferenceRootReduce[Pochhammer[k, z], k]DifferenceRootReduce[Pochhammer[z, k], k]The exponential generating function for Pochhammer:
ExponentialGeneratingFunction[Pochhammer[n, k], n, x]Possible Issues (3)
Large arguments can give results too large to be computed explicitly:
Pochhammer[10. ^ 100, 10 ^ 99]Machine-number inputs can give high‐precision results:
Pochhammer[10. ^ 6, 10. ^ 5]MachineNumberQ[%]As a bivariate function, Pochhammer is not continuous in both variables at negative integers:
Pochhammer[-5, -3]N[%]Pochhammer[-5 .0000001, -3 .00000000001]Use FunctionExpand to obtain a symbolic expression for Pochhammer at negative integers:
FunctionExpand[Pochhammer[-n, -m], (n | m)∈Integers && n > 0 && m > 0]Neat Examples (3)
Plot Pochhammer at infinity:
DensityPlot[Arg[Pochhammer[1 / (x + I y), 1 / (x + I y)]], {x, -0.6, 0.4}, {y, -1 / 2, 1 / 2}, PlotPoints -> 50, ColorFunction -> "FallColors"]Plot Pochhammer for complex arguments:
DensityPlot[Arg[Pochhammer[4.1 Exp[I ϕ1], 5.2 Exp[I ϕ2]]], {ϕ1, -Pi, Pi}, {ϕ2, -Pi, Pi}, PlotPoints -> 50, ColorFunction -> "IslandColors"]Capelli's sum (binomial theorem with Pochhammer symbols):
Sum[Binomial[6, k]Pochhammer[x, k]Pochhammer[y, 6 - k], {k, 0, 6}]//FactorPochhammer[x + y, 6]See Also
Beta Binomial Gamma Factorial FactorialPower Hypergeometric0F1 Hypergeometric1F1 Hypergeometric2F1 QPochhammer DiscreteRatio AppellF1 AppellF2 AppellF3 AppellF4
Function Repository: FactorialSeriesExpansion
Tech Notes
Related Guides
Related Links
History
Introduced in 1988 (1.0) | Updated in 2021 (13.0) ▪ 2022 (13.1)
Text
Wolfram Research (1988), Pochhammer, Wolfram Language function, https://reference.wolfram.com/language/ref/Pochhammer.html (updated 2022).
CMS
Wolfram Language. 1988. "Pochhammer." Wolfram Language & System Documentation Center. Wolfram Research. Last Modified 2022. https://reference.wolfram.com/language/ref/Pochhammer.html.
APA
Wolfram Language. (1988). Pochhammer. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/Pochhammer.html
BibTeX
@misc{reference.wolfram_2026_pochhammer, author="Wolfram Research", title="{Pochhammer}", year="2022", howpublished="\url{https://reference.wolfram.com/language/ref/Pochhammer.html}", note=[Accessed: 13-June-2026]}
BibLaTeX
@online{reference.wolfram_2026_pochhammer, organization={Wolfram Research}, title={Pochhammer}, year={2022}, url={https://reference.wolfram.com/language/ref/Pochhammer.html}, note=[Accessed: 13-June-2026]}