The expression "2n-1" represents a mathematical formula where "n" is a variable that can take on any integer value. When you substitute different integers for "n," the expression generates a sequence of odd numbers. For example, if you set n to 1, the result is 1; if n is 2, the result is 3; and if n is 3, the result is 5. This pattern continues indefinitely. In mathematics, the formula "2n-1" is often used in number theory and algebra. It helps in understanding the properties of odd numbers and their relationships with even numbers, which can be expressed as "2n" where "n" is also an integer. This distinction is fundamental in various mathematical concepts and proofs.