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### Look-and-Say Sequence

```
Date: 02/14/2002 at 17:57:44
From: Vanessa
Subject: Find the 6 missing numbers in number sequences

I can't figure the answer out. I can't seem to find the next six
numbers..

1,11,21,1211,111221,_,_,_,_,_,_.

Thanks.
```

```
Date: 02/15/2002 at 12:21:02
From: Doctor Douglas
Subject: Re: Find the 6 missing numbers in number sequences

Hi, Vanessa, and thanks for writing.

This is a famous sequence known as the "look-and-say" sequence. You
can probably figure out how the whole sequence works just from that
hint alone (try it!).

closely related sequences at the following sites:

121, 111211, 311221 Puzzle
http://mathforum.org/dr.math/problems/joey.10.23.01.html

Look and Say Sequence: MathWorld - Eric Weisstein
http://mathworld.wolfram.com/LookandSaySequence.html

Conway's Constant - Steven Finch
http://pauillac.inria.fr/algo/bsolve/constant/cnwy/cnwy.html

Conway Sequence - Torsten Sillke
http://www.mathematik.uni-bielefeld.de/~sillke/SEQUENCES/series000

I hope this helps.

- Doctor Douglas, The Math Forum
http://mathforum.org/dr.math/
```
Associated Topics:
High School Puzzles
High School Sequences, Series
Middle School Puzzles

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