- Take a decimal number
- Look at the number, visually grouping 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.
- Starting with the number 1, you have one 1 which produces 11.
- Starting with 11, you have two 1’s i.e. 21
- Starting with 21, you have one 2, then one 1 i.e. (12)(11) which becomes 1211
- Starting with 1211 you have one 1, one 2, then two 1’s i.e. (11)(12)(21) which becomes 111221
- Write a program to generate successive members of the look-and-say sequence.
Content is available under GNU Free Documentation License 1.2.