What row is next?

[Tatmtt2120]

What row of numbers comes next?

This is a tough one!

1
11
21
1211
111221
312211
13112221

[-=DoW=- The Fan]

13311211

That is my guess anyway. There is a pattern there that is hard to show here on the forum because it would need RIGHT alignment.

[Panda]

1113213211, 31131211131221

Those are the next two. Fibonacci Sequence baby! :banger:

[Tatmtt2120]

Yup. Panda is correct again. Here is how he got it:

The next row is
1113213211
Starting with the second line, every line describes the line before it. In writing, it is:
One One
Two Ones
One Two One One
etc.
etc.