Explain the pattern and find the next five rows.

Hint: the symbols I chose have nothing to do with the pattern.

Here is how to get the nth row:

For the numbers 1 to n, put a + for a number that is relatively prime to n and a = for a number that has a common factor with n. The nth row is the pattern of symbols that repeats.

1. +

2. +=

3. ++=

4. +=

5. ++++=

6. +===+=

7. ++++++=

8. +=

9. ++=

10. +=+===+=+=

11. ++++++++++=

12. +===+=

Next 5 rows:

13. ++++++++++++=

14. +=+=+===+=+=+=

15. ++=+==++==+=++=

16. +=

17. ++++++++++++++++=