It seems like you've listed a series of numbers: 3, 9, 11, 17. To understand the pattern, we can try analyzing the differences between consecutive terms:

• 9 - 3 = 6
• 11 - 9 = 2
• 17 - 11 = 6

We can see that the differences alternate between 6 and 2. If this pattern continues, we might expect the next term in the sequence to be:

• 17 + 2 = 19

So the next number in the sequence would be 19.

Would you like a more detailed explanation or further examples?

Here are some related questions for exploration:

1. What is the general term for a sequence with alternating differences?
2. How would this sequence change if the differences were consistent?
3. What is the sum of the first 10 terms in a sequence like this?
4. How can we calculate the nth term for sequences with alternating differences?
5. How do you find the sum of an arithmetic sequence?

Tip: When analyzing sequences, always check the differences between consecutive terms; it’s a quick way to identify a pattern!