Describe the pattern in the sequence: 8, 9, 15, ...

The sequence is $8, 9, 15, \dots$.
The difference between the first two terms is $9 - 8 = 1$.
The difference between the second and third terms is $15 - 9 = 6$.

The amount added to each term to get the next term is increasing. The increase in the amount added is $6 - 1 = 5$.

The pattern starts with 8. To get the next term, an increasing amount is added. The amount added increases by 5 each time. For example, 1 is added to 8 to get 9, and then $1+5=6$ is added to 9 to get 15.