It wasn’t. The person that posted the factorization has nothing to do with Anthropic, and has for many years held the leaderboard on GPU-hours applied to factorization and prime search problems. He’s not yet on record as to how this one was done (probably waiting for publication), but there is no reason at all to assume any LLM was involved.

Seems unlikely given claude would not really be effective for this type of problem.

I heard it was a lucky guess