Petals around the rose
    
The game of petals around the rose took Bill Gates 30 minutes to solve.  All I can say is that I solved it way faster, in about three minutes.  The game is part of a special kind of guessing games, called Look-and-say sequence.  Can you solve the following sequence :
1 11 21 1211 111221 312211 13112221 ...
    1 11 21 1211 111221 312211 13112221 ...