Jeff, a little note:

there was no requirement for proper commenting, there was a requirement for 2 min solution.

Cannot say about anybody else, but my typing would not give me a chance to fit the time requirement if I would start typing comments.

And for scalabale solution I would go with Numbers table as well, but for that request spt_values got more than enough numbers. So why waste time on it, if total number could be limited by some business logic.