We are adding by 7 for each progressive term, so we can subtract 97 by 13 and divide the amount by 7 and after add 1 because we have to count the first term as well to get the amount of integers.

We are adding by 7 for each progressive term, so we can subtract 97 by 13 and divide the amount by 7 and after add 1 because we have to count the first term as well to get the amount of integers.