20, 20, 19, 16.. 17, 13, 14, 11,?,?

20, 20, 19, 16.. 17, 13, 14, 11,?,?

Explanation

Looking at the pattern:

20 → 20 (no change)

20 → 19 (decrease by 1)

19 → 16 (decrease by 3)

16 → 17 (increase by 1)

17 → 13 (decrease by 4)

13 → 14 (increase by 1)

14 → 11 (decrease by 3)

Now, we continue the alternating pattern:

11 → 12 (increase by 1)

12 → 9 (decrease by 3)

The next two numbers are 10, 10.