Question: This is a slight variation on an old puzzle that's likely already here, but be sure to check it before you mark it as duplicate.

What are the next three terms in this sequence, and why? 

```
 1  
 11  
 21  
 1211  
 1231  
 131221  
 132231  
 232221  
 ...  

```

Edit:
This is not the Look-and-say sequence as the duplicate links are. It is a variation on the idea of them, but it is not a duplicate in my opinion.

Answer: 
To answer the question more precisely, these are the next three terms:

> 
> 134211  
> 14131231  
> 14231241
> 
> 
> 

This is a variant of the [Look-and-say sequence](http://en.wikipedia.org/wiki/Look-and-say_sequence). This particular variant is [already in OEIS](https://oeis.org/A007890)! It is formed by summarizing the terms of the previous number, but all at once in descending order, which is different from the look and say sequence. 

For example, the sequence goes from 1211 to 1231 because:  

The previous term contained one two. (12)  

The previous term contained three ones. (31)  

**-> 1231**. 

Another example, the sequence goes from 132231 to 232221 because:  

The previous term contained two threes. (23)  

The previous term contained two twos. (22)  

The previous term contained two ones. (21)  

**-> 232221.**
This is like that look-say sequence thing. Each line describes the numbers of the line before.

First line has one 1, so the second line is 11. The second line has 2 1's, so the third line is 21. The third line has one two and one one, so the fourth line is 1211 etc.