The next number in the sequence is 27.
11
11
11.
It is 129.
27.
The next figure would be 21, followed by 11 & 10.
22
The next number in the sequence is 27.
18
37.
It's, 7n+6
This is a peculiar number sequence which follows the following rule: +7, -4, +8, -3, +9, -2... The next few functions would be +10, -1, +11, -0 And thus the next few numbers in the sequence would be 17+10=27, 27-1=26, and so on. The sequence in total goes 2, 9, 5, 13, 10, 19, 17, 27, 26, 37, 37.
20
The next number in the sequence is 122. The pattern involves adding increasing increments to each number in the sequence: +14, +10, +11, +13.
The next number is 27. Nice puzzle! The reason is on discussion page, for those who are still working on it.
22