When you run the program the highlight will initially be on the ‘Define Seq.’ option, since that is the first thing that must be done. You then have a choice of supplying either a and d or the first two terms of an AP.
You can then use the menu to find the nth term or the sum to n terms.
The third option is to give a ‘List of terms’. This will create a matrix with columns containing Tn and Sn. The matrix will be deleted after being displayed to save memory. Matrix M0 will be overwritten by this. For large values of n, this can take a minute or so to complete. Memory may also be a problem for large values of n if you have a number of other programs or notes on the calculator.

AP: Separate Tn

Given two separated terms (ie T7=6 and T15=30) this will find the values of a and d defining the AP.