# How to Calculate a Sequence's Terms by Using the Sequence Expression

If you're given a few terms of a sequence, you can often use these terms to find the general formula for the sequence. If you're given the general formula (complete with *n* as the variable), you can find the *n*^{th} term of the sequence by plugging in the position number for *n.*

The general formula for any sequence involves the letter *n,* which is the position of the term in the sequence (the first term would be *n* = 1, and the 20th term would be *n* = 20), as well as the rule to find each term. You can find any term of a sequence by plugging *n* into the general formula, which gives you specific instructions on what to do with this value *n.*

Unless otherwise noted, the first term of any sequence {*a** _{n}*} begins with

*n*= 1. The next

*n*always goes up by 1.

For example, you can use the formula to find the first three terms of

Find

*a*_{1}first by plugging in 1 wherever you see*n.*Continue plugging in consecutive integers for

*n.*This process gives you terms two and three: