**1, 11, 21 Riddle** is a tricky riddle and here is the answer. It’s a mathematical Puzzle in which you need to guess the next sequence number. This kind of riddles has a pattern in it which you have to find out.

**Question:** 1, 11, 21, 1211, 111221, 312211. What is the next number in the sequence?

**Answer: **The answer to **“1 11 21 Riddle”** is** “13112221.”**

The next sequence after the 312211 will be 13112221. The pattern in this puzzle is:

- In each number one is increasing and decreasing (once places).
- If you look the 2 number in Tens place its also increasing after each sequence.
- Then see the third line after the 2 the one is also increasing and decreasing.
- At last we will add one as the one is added every time as with the 2.