Constant made an important point: infinitely many rules are consistent with the evidence no matter how many instances you test. Therefore any guess you make must be influenced by prior expectations. And like lusispedro said, based on experience students probably put a lot more weight on rules based on simple equations than rules based on inequalities.
I’m sure I could get the percentage of people who guess correctly down to 0% by simply choosing the perfectly valid rule: “sequences (a,b,c) such that EITHER a less than b less than c OR b is a multiple of 73.”
Why? Because rules of that sort are given low weight in subjects’ priors.