Ruby example added to description.

Nice kata, I implemented a solution I'd imagine is somewhat more optimized than a naive one.. at least for the longer, complicated, perhaps even commented programs :D

This kata was nifty! Clever design as naive algorithms don't work due to the breathtaking sizes the test cases have.
After I've solved it, I learned a new tidbit of algorithm magic that may help me conquer the dark forces of evil looping data sets where needed.

The description in Ruby version could be indeed made better with examples; I first looked over the "returns a single-dimensional array representing Pascal's Triangle to the n-th level." as a possible typo ("why not arrays in arrays? could it mean a single row instead?").

Also, it would be helpful if the test showed exactly what went wrong - I apparently had some problems with floating point accuracy on my first attempt, failing on larger numbers of the triangle.