Puzzle

HERE'S A puzzle suggested by an item on the recent Radio 4 Puzzle Panel series: What is the next number in this series:

1, 11, 21, 1112, 3112, 211213, 312213, 212223, 114213... ?

(Answer tomorrow)

Yesterday's answers:

1) T (take the initial letters of the words in the question and move them one step in the alphabet)

2) Q (initial letters of "To be or not to be...)