This sequence (as seen on Wikipedia) begins as follows:
- 1
- 11
- 21
- 1211
- 111221
- ...
where each member is formed by reading the member before (e.g. following 21 we have "one 2, one 1", then "one 1, one 2, two 1", and so forth).
The look_and_say template, with template parameter n, calculates the nth
member of the look-and-say sequence (where 1 is the zeroth member
look_and_say<0>::t, so we are offset by one from OEIS
A005150). It encodes each member by digit in a
Lisp-like list type with typedef t, which affords convenient calculation. You
can print it with the print function of the print_list template. A simple
example usage can be seen in main.cpp.