I found an answer from www.quora.com

What is the next number in this sequence: 1, 11, 21, 1211, 111221 ...

Puzzle: What will be the next number in this incredibly tough sequence: 6, 21 ... What is the next element of the following series: (1),(11),(21), (1211), (1231), ( 131221). .... 312211 -> "1three, 1 one, 2 twos, 2 ones"; Seventh member-> 13112221 ...

For more information, see What is the next number in this sequence: 1, 11, 21, 1211, 111221 ...

I found an answer from challenges.wolfram.com

Look and Say Sequence | Wolfram Challenges

Now look at the second term 11 and say, "two ones" to get the third term 21. Look at the third term ... term 1211. This gives the sequence 1, 11, 21, 1211, 111221, … ... Out[2]= {1, 11, 21, 1211, 111221, 312211, 13112221, 1113213211. In[3]:=.

For more information, see Look and Say Sequence | Wolfram Challenges

I found an answer from mathworld.wolfram.com

Look and Say Sequence -- from Wolfram MathWorld

The integer sequence beginning with a single digit in which the next term is obtained ... 1, A005150, 1, 11, 21, 1211, 111221, 312211, 13112221, 1113213211, .

For more information, see Look and Say Sequence -- from Wolfram MathWorld

I found an answer from en.wikipedia.org

Look-and-say sequence - Wikipedia

In mathematics, the look-and-say sequence is the sequence of integers beginning as follows: 1 ... 111221 is read off as "three 1s, two 2s, then one 1" or 312211. ..... the puzzle "What is the next number in the sequence 1, 11, 21, 1211, 111221?

For more information, see Look-and-say sequence - Wikipedia

I found an answer from answers.yahoo.com

what is the pattern?: 1, 11, 21, 1211, 111221, 312211, 13112221 ...

1 = one 11 = one one (the preceding step had one one) 21 = two one (the ... When you say this aloud you get the next sequence. B. 1 1. That's 2 ones, so C is:

For more information, see what is the pattern?: 1, 11, 21, 1211, 111221, 312211, 13112221 ...

I found an answer from br.answers.yahoo.com

what follows on : 1 , 11 , 21 ,1211 ,111221 ,312211 , 13112221 ...

And that is one one, one two, and two ones: "111221" ... Examine carefully the following sequences of numbers: 1, 11, 21, 1211, 111221, 312211, 13112221, ...

For more information, see what follows on : 1 , 11 , 21 ,1211 ,111221 ,312211 , 13112221 ...

I found an answer from it.answers.yahoo.com

1 11 21 1211 111221 312211 13112221 ect.?

giuro ke c'ho messo 5 minuti per arrivarci.. ma alla fine ce l'ho fatta 31131211131221.. bello xò!!

For more information, see 1 11 21 1211 111221 312211 13112221 ect.?