# Find the next line in the sequence

1. Oct 20, 2004

### hailee

Hello, as part of a standardized test practice booklet that I have been doing on my own, I was given a problem and told to find the next line in the sequence. I have attempted it several times, and asked many friends, but we can not seem to get it.
It will probably turn out to be something terribly obvious,and once it is figured out i will feel incredibly lame, but I will go crazy if I do not find out!
The sequence is as follows:
1
11
21
1211
111221
312211
13112221

I've tried many things with it, but none of them have worked out. At first glance of course, you see the value increasing by 10, but once you see the fourth column, that obviously does not work.

Any input would be appreciated.
Thank you.

[.hailee.]

2. Oct 20, 2004

### UrbanXrisis

there is one one (11)
there are two ones (21)
there is one two and one one (1211)

and on...

13112221
1113213211 (look at the previous number....there is one one, one three, two ones, three twos, and one one

get it?

what test is this for?!?! it sounds like a trick question

btw, welcome to PF hailee

Last edited: Oct 20, 2004
3. Oct 20, 2004

### hailee

It is from a booklet type thing that my teacher gave me, saying it would help me in standardized test preparations.. It has lots of problems similar to this, and I have been able to solve many, but a few of them I have difficulty with. But they always seem to have obvious enough answers, so maybe I'm simply not working hard enough or long enough on them. Or,I could be over working them and not seeing the obvious answers!

So, going by your given pattern, the next sequence would be
>13213211
Correct?

And thank you so much. I appreciate it.

[.hailee.]

4. Oct 20, 2004

### UrbanXrisis

you almost got it

as I posted above...
13112221
1113213211 (look at the previous number....there is one one, one three, two ones, three twos, and one one)

5. Oct 20, 2004

### hailee

oh geez. i didn't see that you had posted what the next one would be. Once i thought I saw the pattern I started trying to find the next one. And I was wrong, hah. But I'm fairly sure that I get it now.
So, for understandings sake,
13112221
>1113213211
>31131211131221 ?

I think?

[.hailee.]

6. Oct 20, 2004

### UrbanXrisis

yes! thats correct