What is the Pattern Puzzle - Solution

The Puzzle:

What is the Pattern
Write down the next line in the following pattern:





Our Solution:

Each row describes the grouping of the digits in the line above.

The top row "1" has one one, so we write "11" for the second row.
The second row "11" has two ones, so we write "21" for the third row.
And so on.

To describe the line: 31131211131221
We say: one three, two ones, one three, one one, one two, three ones, one three, one one, two twos and one one.

Which is: 13211311123113112211


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