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Binomial
Details

- Integer mathematical function, suitable for both symbolic and numerical manipulation.
- Binomial is also known as combinations and as choose function.
- Binomial gives the symmetric coefficients for negative integer
. Use PascalBinomial for coefficients that preserve Pascal's identity for all integer values. Binomial and PascalBinomial agree except for negative integer
.
- In general,
is defined by
or suitable limits of this.
- When
is a negative integer,
. »
- The particular limit chosen preserves the symmetry rule
for all complex
and
. »
- Pascal's identity
is satisfied for almost all
and
, but violated for
. »
- For integers and certain other special arguments, Binomial automatically evaluates to exact values.
- Binomial is automatically evaluated symbolically for simple cases; FunctionExpand gives results for other cases. »
- Binomial can be evaluated to arbitrary numerical precision.
- Binomial automatically threads over lists.
- Binomial can be used with Interval and CenteredInterval objects. »
Background & Context
- Binomial represents the binomial coefficient function, which returns the binomial coefficient
of
and
. For non-negative integers
and
, the binomial coefficient has value
, where
is the Factorial function. By symmetry,
. The binomial coefficient is important in probability theory and combinatorics and is sometimes also denoted
- For non-negative integers
and
, the binomial coefficient
gives the number of subsets of length
contained in the set
. This is also the number of distinct ways of picking
elements (without replacement and ignoring order) from the first
positive integers and for this reason is often voiced as "
choose
".
- The binomial coefficient lies at the heart of the binomial formula, which states that for any non-negative integer
,
. This interpretation of binomial coefficients is related to the binomial distribution of probability theory, implemented via BinomialDistribution. Another important application is in the combinatorial identity known as Pascal's rule, which relates the binomial coefficient with shifted arguments according to
.
- Expressing factorials as gamma functions generalizes the binomial coefficient to complex
and
as
. Using the symmetry formula
for integer
and
and complex
then allows the definition of the binomial coefficient to be extended to negative integer arguments, making it continuous at all integer arguments as well as continuous for all complex arguments except for negative integer
and noninteger
(in which case it is infinite). This definition for negative
and integer
, given by
if
,
if
and 0 otherwise, is in agreement with both the binomial theorem and most combinatorial identities (with a few special exceptions).
- Binomial coefficients are generalized by multinomial coefficients. Multinomial returns the multinomial coefficient (n;n1,…,nk) of given numbers n1,…,nk summing to
, where
. The binomial coefficient
is the multinomial coefficient (n;k,n-k).
Examples
open allclose allBasic Examples (5)Summary of the most common use cases

https://wolfram.com/xid/0cq0qv3e-exyjo0


https://wolfram.com/xid/0cq0qv3e-34wfwl


https://wolfram.com/xid/0cq0qv3e-omwgp3

Plot over a subset of the reals as a function of its first parameter:

https://wolfram.com/xid/0cq0qv3e-gi13sj

Plot over a subset of the reals as a function of its second parameter:

https://wolfram.com/xid/0cq0qv3e-kvw8g

Plot over a subset of the complexes:

https://wolfram.com/xid/0cq0qv3e-kiedlx

Scope (35)Survey of the scope of standard use cases
Numerical Evaluation (7)

https://wolfram.com/xid/0cq0qv3e-l274ju


https://wolfram.com/xid/0cq0qv3e-cksbl4

Evaluate for half-integer arguments:

https://wolfram.com/xid/0cq0qv3e-klrel


https://wolfram.com/xid/0cq0qv3e-b0wt9

The precision of the output tracks the precision of the input:

https://wolfram.com/xid/0cq0qv3e-y7k4a


https://wolfram.com/xid/0cq0qv3e-c3zszs


https://wolfram.com/xid/0cq0qv3e-hfml09

Evaluate efficiently at high precision:

https://wolfram.com/xid/0cq0qv3e-di5gcr


https://wolfram.com/xid/0cq0qv3e-bq2c6r

Compute worst-case guaranteed intervals using Interval and CenteredInterval objects:

https://wolfram.com/xid/0cq0qv3e-h0d6g


https://wolfram.com/xid/0cq0qv3e-dj6d9x

Or compute average-case statistical intervals using Around:

https://wolfram.com/xid/0cq0qv3e-cw18bq

Compute the elementwise values of an array:

https://wolfram.com/xid/0cq0qv3e-thgd2

Or compute the matrix Binomial function using MatrixFunction:

https://wolfram.com/xid/0cq0qv3e-o5jpo

Specific Values (4)
Values of Binomial at particular points:

https://wolfram.com/xid/0cq0qv3e-nww7l

Binomial for symbolic n:

https://wolfram.com/xid/0cq0qv3e-fc9m8o


https://wolfram.com/xid/0cq0qv3e-jdd1mk


https://wolfram.com/xid/0cq0qv3e-e41pf2

Note that this is zero on all integers away from :

https://wolfram.com/xid/0cq0qv3e-1ys7jj

Find a value of n for which Binomial[n,2]=15:

https://wolfram.com/xid/0cq0qv3e-f2hrld


https://wolfram.com/xid/0cq0qv3e-gxsukt

Visualization (3)
Plot the Binomial as a function of its parameter n:

https://wolfram.com/xid/0cq0qv3e-bhh92c

Plot the Binomial as a function of its parameter :

https://wolfram.com/xid/0cq0qv3e-bzo8ib


https://wolfram.com/xid/0cq0qv3e-cjk9wl


https://wolfram.com/xid/0cq0qv3e-b41shq

Function Properties (12)
Real domain of Binomial as a function of its parameter n:

https://wolfram.com/xid/0cq0qv3e-cl7ele

Real domain of Binomial as a function of its parameter m:

https://wolfram.com/xid/0cq0qv3e-bhcc


https://wolfram.com/xid/0cq0qv3e-de3irc


https://wolfram.com/xid/0cq0qv3e-d1f4tb

Function range of Binomial:

https://wolfram.com/xid/0cq0qv3e-d8uhh9

Binomial has the mirror property :

https://wolfram.com/xid/0cq0qv3e-heoddu

Compute sums involving Binomial:

https://wolfram.com/xid/0cq0qv3e-m4i2hj


https://wolfram.com/xid/0cq0qv3e-d5f73c

When is positive,
is an analytic function of both variables:

https://wolfram.com/xid/0cq0qv3e-g1bb8w

This is not true for negative :

https://wolfram.com/xid/0cq0qv3e-yoc2vi

is neither non-decreasing nor non-increasing:

https://wolfram.com/xid/0cq0qv3e-2ra8g


https://wolfram.com/xid/0cq0qv3e-c9npzh


https://wolfram.com/xid/0cq0qv3e-b5buvp


https://wolfram.com/xid/0cq0qv3e-patce


https://wolfram.com/xid/0cq0qv3e-bcrbvs

Binomial is neither non-negative nor non-positive:

https://wolfram.com/xid/0cq0qv3e-dvzykj


https://wolfram.com/xid/0cq0qv3e-kpi9jh

has singularities and discontinuities where
is a negative integer:

https://wolfram.com/xid/0cq0qv3e-tizf8k


https://wolfram.com/xid/0cq0qv3e-g7sk2p

is neither convex nor concave:

https://wolfram.com/xid/0cq0qv3e-l0srvu

TraditionalForm formatting:

https://wolfram.com/xid/0cq0qv3e-zvmzu

Differentiation (3)
First derivative with respect to :

https://wolfram.com/xid/0cq0qv3e-krpoah

Higher derivatives with respect to :

https://wolfram.com/xid/0cq0qv3e-z33jv

Plot the higher derivatives with respect to for
:

https://wolfram.com/xid/0cq0qv3e-fxwmfc

First derivative with respect to :

https://wolfram.com/xid/0cq0qv3e-pgq6et

Series Expansions (4)
Find the Taylor expansion using Series:

https://wolfram.com/xid/0cq0qv3e-ewr1h8

Plots of the first three approximations around :

https://wolfram.com/xid/0cq0qv3e-binhar

Find the series expansion at Infinity:

https://wolfram.com/xid/0cq0qv3e-ht5z5a

Find series expansion for an arbitrary symbolic direction :

https://wolfram.com/xid/0cq0qv3e-rkoq2k

Taylor expansion at a generic point:

https://wolfram.com/xid/0cq0qv3e-jwxla7

Function Identities and Simplifications (2)

https://wolfram.com/xid/0cq0qv3e-fntli3


https://wolfram.com/xid/0cq0qv3e-ge3pv7


https://wolfram.com/xid/0cq0qv3e-c93h2q

Generalizations & Extensions (2)Generalized and extended use cases
Infinite arguments give symbolic results:

https://wolfram.com/xid/0cq0qv3e


https://wolfram.com/xid/0cq0qv3e

Binomial threads elementwise over lists:

https://wolfram.com/xid/0cq0qv3e

Applications (11)Sample problems that can be solved with this function
There are ways to choose
elements without replacements from a set of
elements:

https://wolfram.com/xid/0cq0qv3e-bzis8

Check with direct enumeration:

https://wolfram.com/xid/0cq0qv3e-drjmvc


https://wolfram.com/xid/0cq0qv3e-bp5vcd

There are ways to choose
elements with replacement from a set of
elements:

https://wolfram.com/xid/0cq0qv3e-basc4x

Check with direct enumeration:

https://wolfram.com/xid/0cq0qv3e-eck30t


https://wolfram.com/xid/0cq0qv3e-fqjyd5

There are ways to arrange
indistinguishable objects of one kind, and
indistinguishable objects of another kind:

https://wolfram.com/xid/0cq0qv3e-bc420f


https://wolfram.com/xid/0cq0qv3e-zyhq5


https://wolfram.com/xid/0cq0qv3e-oqvidf

Illustrate the binomial theorem:

https://wolfram.com/xid/0cq0qv3e-elh4b


https://wolfram.com/xid/0cq0qv3e-ddn5wi


https://wolfram.com/xid/0cq0qv3e-bybnro


https://wolfram.com/xid/0cq0qv3e-cxa6k4


https://wolfram.com/xid/0cq0qv3e-mczzkd

Plot Binomial in the arguments' plane:

https://wolfram.com/xid/0cq0qv3e-ig68fq

Plot the logarithm of the number of ways to pick elements out of
:

https://wolfram.com/xid/0cq0qv3e-j6x0v6

Compute higher derivatives of a product of two functions:

https://wolfram.com/xid/0cq0qv3e-dq0poq


https://wolfram.com/xid/0cq0qv3e

PDF of the binomial probability distribution:

https://wolfram.com/xid/0cq0qv3e


https://wolfram.com/xid/0cq0qv3e

Bernstein polynomials are defined in terms of Binomial:

https://wolfram.com/xid/0cq0qv3e-ctuozw


https://wolfram.com/xid/0cq0qv3e-4cmm9

Properties & Relations (11)Properties of the function, and connections to other functions
On the integers, Binomial[n,m] equals :

https://wolfram.com/xid/0cq0qv3e-k4fwj3

This can be expressed as for
and
for
:

https://wolfram.com/xid/0cq0qv3e-zru3f9

An alternative formula on the integers:

https://wolfram.com/xid/0cq0qv3e-fnhbix

Pascal's identity is satisfied almost everywhere:

https://wolfram.com/xid/0cq0qv3e-x2cynh


https://wolfram.com/xid/0cq0qv3e-jkv9k6

PascalBinomial satisfies the identity everywhere, including the origin:

https://wolfram.com/xid/0cq0qv3e-wasx40

The symmetry rule holds for all values of
and
:

https://wolfram.com/xid/0cq0qv3e-i67mi5

PascalBinomial performs simple evaluations for symbolic arguments:

https://wolfram.com/xid/0cq0qv3e-jf1l2z

For more complex expressions, it will avoid automatic expansion:

https://wolfram.com/xid/0cq0qv3e-4m4kxv

Use FunctionExpand with conditions to achieve appropriate simplifications:

https://wolfram.com/xid/0cq0qv3e-ty4v8l

Use FullSimplify to simplify expressions involving binomial coefficients:

https://wolfram.com/xid/0cq0qv3e-ctylci

Use FunctionExpand to expand into Gamma functions:

https://wolfram.com/xid/0cq0qv3e

Sums involving Binomial:

https://wolfram.com/xid/0cq0qv3e


https://wolfram.com/xid/0cq0qv3e


https://wolfram.com/xid/0cq0qv3e


https://wolfram.com/xid/0cq0qv3e

Find the generating function Binomial:

https://wolfram.com/xid/0cq0qv3e

Binomial can be represented as a DifferenceRoot:

https://wolfram.com/xid/0cq0qv3e-d7mw27


https://wolfram.com/xid/0cq0qv3e-ojcks5

The generating function for Binomial:

https://wolfram.com/xid/0cq0qv3e-pz93yz

The exponential generating function for Binomial:

https://wolfram.com/xid/0cq0qv3e-g1j8nf

Possible Issues (3)Common pitfalls and unexpected behavior
Large arguments can give results too large to be computed explicitly:

https://wolfram.com/xid/0cq0qv3e


Machine-number inputs can give high‐precision results:

https://wolfram.com/xid/0cq0qv3e


https://wolfram.com/xid/0cq0qv3e

As a bivariate function, Binomial is not continuous in both variables at negative integers:

https://wolfram.com/xid/0cq0qv3e-oluz92

The value of Binomial at negative integers is determined via Binomial[n,m]Binomial[n,n-m]:

https://wolfram.com/xid/0cq0qv3e


https://wolfram.com/xid/0cq0qv3e-ec2vnx


https://wolfram.com/xid/0cq0qv3e-kkw2gg

Neat Examples (7)Surprising or curious use cases
Construct a graphical version of Pascal's triangle:

https://wolfram.com/xid/0cq0qv3e-q15ovm

Extend the triangle to negative integers; unlabeled points indicate a zero value:

https://wolfram.com/xid/0cq0qv3e-hx7umr

PascalBinomial, by contrast, zeroes out the top-left sector where both inputs are negative:

https://wolfram.com/xid/0cq0qv3e-sdo9vl


https://wolfram.com/xid/0cq0qv3e-blpqjq

Closed‐form inverse of Hilbert matrices:

https://wolfram.com/xid/0cq0qv3e-mq2uki


https://wolfram.com/xid/0cq0qv3e-f9gupa

Nested binomials over the complex plane:

https://wolfram.com/xid/0cq0qv3e

Plot Binomial at infinity:

https://wolfram.com/xid/0cq0qv3e

Plot Binomial for complex arguments:

https://wolfram.com/xid/0cq0qv3e

Plot Binomial at Gaussian integers:

https://wolfram.com/xid/0cq0qv3e

Wolfram Research (1988), Binomial, Wolfram Language function, https://reference.wolfram.com/language/ref/Binomial.html.
Text
Wolfram Research (1988), Binomial, Wolfram Language function, https://reference.wolfram.com/language/ref/Binomial.html.
Wolfram Research (1988), Binomial, Wolfram Language function, https://reference.wolfram.com/language/ref/Binomial.html.
CMS
Wolfram Language. 1988. "Binomial." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/Binomial.html.
Wolfram Language. 1988. "Binomial." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/Binomial.html.
APA
Wolfram Language. (1988). Binomial. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/Binomial.html
Wolfram Language. (1988). Binomial. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/Binomial.html
BibTeX
@misc{reference.wolfram_2025_binomial, author="Wolfram Research", title="{Binomial}", year="1988", howpublished="\url{https://reference.wolfram.com/language/ref/Binomial.html}", note=[Accessed: 25-March-2025
]}
BibLaTeX
@online{reference.wolfram_2025_binomial, organization={Wolfram Research}, title={Binomial}, year={1988}, url={https://reference.wolfram.com/language/ref/Binomial.html}, note=[Accessed: 25-March-2025
]}