A particular instance of a generalized statement. A single counterexample will disprove a generalized claim, but examples do not provide proof. For example, the number of regions created by joining n distinct points on a circle is at most 1, 2, 4, 8, 16 for 1 ≤ n ≤ 5 which are in the form 2n−1. However these 5 examples do not verify that result and indeed for n = 6, there are at most 31 regions produced, so the general expression cannot be 2n−1. See Moser’s circle problem.