Programming Challenge: Find a Particular Prime Number

[Thomas Okken]

Yes, the search space is too large for pure brute-force, and once you start thinking about how to reduce it, before you know it you've solved the puzzle by reasoning alone -- although we both demonstrated how easily you can get that wrong. :-)

I thought this might be a puzzle that others had figured out and written about before this, but all I found was this: http://www.matheboard.de/archive/547281/thread.html