Geometric sequences

A geometric sequence is a list of numbers where each term is obtained by multiplying the previous term by a fixed, constant factor called the common ratio. For example, in the sequence 2, 6, 18, 54, each number is multiplied by 3 to get the next. These sequences grow or shrink exponentially, not linearly, and are commonly used to model situations like population growth, radioactive decay, or investment returns, where the change rate is proportional to the current amount.