Medium

What number comes next: 1, 11, 21, 1211, 111221, ...?

Show Answer

Answer: 312211
More information: John Conway's "look and say" sequence has no digits other than 1, 2, and 3 in it, unless the seed number contains such a digit or a run of more than three of the same digit. A degenerate sequence appears with the seed of 22.