[mattkrause]

Something like this is in Josh Tannenbaum’s PhD thesis, where he calls it “The Numbers Game.” https://dspace.mit.edu/handle/1721.1/16714

He uses the game to show that people do something akin to Bayesian updating over possible concepts and have certain intuitive priors (e.g., ‘even numbers’ is a priori more likely than {2, 7, 9, 31}).

This is briefly mentioned at the beginning of Kevin Murphy’s Machine Learning: A Probabilistic Approach, so you might also have encountered it there.