Anthropic says one of its unreleased Claude models stumbled into a mathematical breakthrough while trying to solve a problem that has baffled researchers since 1859. Anthropic wrote, “We don’t expect that the techniques Claude used will lead to proving the Riemann hypothesis. But its work serves as the latest example of the speed of progress in AI models’ mathematical capabilities.” How the model reached the resultAnthropic said the research model worked across two Claude Code sessions and generated 31 million output tokens. Anthropic’s result has not gone through the normal academic peer-review process, and Claude did not solve the Riemann hypothesis.