I have in mind a rule governing sequences of numbers. The sequence 2-4-8 fits this rule. Your job is to find out the rule by presenting me with additional sequences of three numbers: I will then tell you whether they fit the rule or not. Once you are satisfied that you know the rule, write it down. You win if your rule is correct; I win if it is wrong.
Note: for some weird reason, it only works if all your numbers have the same number of digits: if you want to enter 8, 10, 12, type 08, 10, 12. (But 2, 4, 6 is fine.)
Do they obey the rule?
If you think you know the rule, enter it here:
(Refresh the page to write a new rule.)