What is the next number in this look and say sequence:

3, 13, 1113, 3113, 132113, 1113122113, 311311222113, ?

This is a recursively defined sequence of numbers which is commonly called as Look and say sequence.

The sequence can be defined as:

# Take a decimal number

# Look at the number, group consecutive runs of the same digit.

# Say the number, from left to right, group by group; as how many of that digit there are - followed by the digit grouped.

# This becomes the next number of the sequence.

3, 13, 1113, 3113, 132113, 1113122113, 311311222113, ?

3 = one three

13 = one one, one three

1113 = three one, one three

3113 = one three, two one, one three

132113 = one one, one three, one two, two one, one three

1113122113 = three one, one three, one one,two two, two one, one three

311311222113 = one three, two one, one three, two one, three two, two one, one three 13211321322113

So the next number in this look and say sequence is **13211321322113**

13211321322113