Answer:
17
Step-by-step explanation:
The answer is 17 because We noticed that 5 is 4 more than 1, 9 is 4 more than 5, and 13 is 4 more than 9. They are all a +4 pattern so you just simply add 4 to 13 which is 13 + 4 + 17 So our answer is 17
