Given the first term and the difference determine the rule for a arithmetic sequence

The video tutorial explains how to find and simplify the formula for a sequence, specifically focusing on a sub n. It demonstrates the process of simplifying the formula to 12n - 5 and applying it to find specific terms like a sub 16. The tutorial emphasizes understanding the rule for any value of a sub n and reviews the key concepts discussed in previous classes.

What is the simplified rule for a sub n that the teacher emphasizes?

Explain the significance of the variable n in the formula discussed.