My daughter was trying to solve a peg solitaire puzzle on a triangular board, and to impress her I needed to find a solution. A billion tries later I had one, and then I wanted all of them.
The starting positions fall into four groups. I found three by hand, but the one in the middle (index 04) resisted, so I wrote this solver: a brute-force search in Python that tries every sequence of jumps from a given start. It took three hours late at night, so the code is a bit rough, but it works.