The next number is 27. Nice puzzle! The reason is on discussion page, for those who are still working on it.
5
21
The next number in the sequence would be 25.
311311122110
120
5
21
The next number in the sequence would be 25.
266
311311122110
120
The next number in the sequence is 480
35
Consecutive terms in the sequence are found by dividing by 2 and adding 2. Therefore, after the number 10 comes 10/2 + 2 = 7.
5
27.
next in the sequence: 10,20,30,20