# The Excel SERIESSUM Function

## Basic Description

The Excel SERIESSUM function returns the sum of a power series, based on the following power series expansion:

The syntax of the function is :

SERIESSUM( x, n, m, coefficients )

Where the function arguments are:

 x - The input value to the power series n - The initial power, to which x is to be raised m - The step size that n is increased by, on each successive power of x coefficients - An array of coefficients that multiply each successive power of x

The number of values in the supplied coefficients array defines the number of terms in the power series. This is illustrated in the following example.

## Excel Seriessum Function Examples

### Example 1

In the example below, the Excel Seriessum function is used to calculate the power series:

51 + 52 + 53 + 54 + 55
Formulas:
A
1=SERIESSUM( 5, 1, 1, {1,1,1,1,1} )
Results:
A
13905

## Example 2

In the example below, the Excel Seriessum function calculates the power series:

1 * 21 + 2 * 23 + 3 * 25 + 4 * 27 + 5 * 29
Formulas:
A
1=SERIESSUM( 2, 1, 2, {1,2,3,4,5} )
Results:
A
13186

More details and examples of the Excel Seriessum function are provided on the Microsoft Office website.

## Seriessum Function Errors

If you get an error from the Excel Seriessum Function, this is likely to be one of the following:

Common Errors
 #VALUE! - Occurs if any of the supplied arguments are non-numeric #NAME? - Occurs when Analysis ToolPak add-in is not enabled in your Excel. You will need to enable the add-in if you want to use the Excel Seriessum function.