The range of a sequence is merely a set that defines the sequence. The range is usually represented by the set {x₁}, {x₂}, {x₃}, and so on; it is also written as {x_n; n = 1, 2, 3, …}. For example, in the question above, the data for each day that the scientist collects from his weather experiment is the range. Another example is the range of the sequence {(-1)ⁿ}_n ≥ ₁: It is the two-element set {-1, 1}.