# FindGeneratingFunction

FindGeneratingFunction[{a0,a1,},x]

attempts to find a simple generating function in x whose n series coefficient is an.

FindGeneratingFunction[{{n0,a0},{n1,a1},},x]

attempts to find a simple generating function whose ni series coefficient is ai.

# Details and Options

• The sequence elements an can be either exact numbers or symbolic expressions.
• FindGeneratingFunction finds results in terms of a wide range of integer functions, as well as implicit solutions to difference equations represented by DifferenceRoot.
• If FindGeneratingFunction cannot find a simple generating function that yields the specified sequence, it returns unevaluated.
• FindGeneratingFunction has the following options:
•  FunctionSpace Automatic where to look for candidate simple generating functions Method Automatic method to use TimeConstraint 10 how many seconds to search a particular function space or perform a transformation ValidationLength Automatic sequence length used to validate a candidate generating function found
• FindGeneratingFunction[list,x] by default uses earlier elements in list to find candidate simple generating functions, then validates the generating functions by looking at later elements.
• FindGeneratingFunction[list,x] only returns functions that correctly reproduce all elements of list.

# Examples

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## Basic Examples(2)

Find a generating function for a sequence:

A periodic sequence:

## Scope(2)

Rational functions:

Hypergeometric functions:

## Generalizations & Extensions(1)

FindGeneratingFunction works on arbitrary exact numbers or symbolic expressions:

## Properties & Relations(1)

Use FindSequenceFunction to find a generating function of a sequence:

Verify:

Wolfram Research (2008), FindGeneratingFunction, Wolfram Language function, https://reference.wolfram.com/language/ref/FindGeneratingFunction.html.

#### Text

Wolfram Research (2008), FindGeneratingFunction, Wolfram Language function, https://reference.wolfram.com/language/ref/FindGeneratingFunction.html.

#### CMS

Wolfram Language. 2008. "FindGeneratingFunction." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/FindGeneratingFunction.html.

#### APA

Wolfram Language. (2008). FindGeneratingFunction. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/FindGeneratingFunction.html

#### BibTeX

@misc{reference.wolfram_2024_findgeneratingfunction, author="Wolfram Research", title="{FindGeneratingFunction}", year="2008", howpublished="\url{https://reference.wolfram.com/language/ref/FindGeneratingFunction.html}", note=[Accessed: 04-August-2024 ]}

#### BibLaTeX

@online{reference.wolfram_2024_findgeneratingfunction, organization={Wolfram Research}, title={FindGeneratingFunction}, year={2008}, url={https://reference.wolfram.com/language/ref/FindGeneratingFunction.html}, note=[Accessed: 04-August-2024 ]}