Really surprised that 1stproof.org was submitted three times and never made front page at HN.
https://hn.algolia.com/?q=1stproof
This is exactly the kind of challenge I would want to judge AI systems based on. It required ten bleeding-edge-research mathematicians to publish a problem they've solved but hold back the answer. I appreciate the huge amount of social capital and coordination that must have taken.
I'm really glad they did it.