# Formula to this pattern?

I have this pattern:

1
11
21
1211
111221


I'm guessing it's a fibo pattern, been at it for hours now. Anyone know?

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I know where it comes from - each line is what you get when you speak the previous line - one one; two ones; one two, one one; etc. –  Gerry Myerson Jul 5 '12 at 12:51
Hint: Not Fibonacci. Read the digits out loud to find the pattern. –  Johannes Kloos Jul 5 '12 at 12:51
Thank you guys! –  Karl Morrison Jul 5 '12 at 12:55
So next would be: 312211 –  Karl Morrison Jul 5 '12 at 12:56
You could also check out oeis.org/A005150 –  Ross Millikan Jul 5 '12 at 12:59