👉 In mathematics, "outsumming" is a concept that refers to a sequence of numbers where each number in the sequence appears exactly once. In other words, all the elements in the sequence are distinct and appear in an order that is not necessarily sequential. For example, consider the sequence 1, 2, 3, 4, 5, which has five distinct elements. This sequence can be thought of as "outsumming" because it does not have a direct predecessor or