What is a geometric sequence?

In a geometric sequence, each term is obtained by multiplying a constant or variable value to the previous term.
A geometric sequence is also called a second-degree arithmetic sequence.
The formula to calculate the nth term of a geometric sequence is an = a1 * r^(n-1), where a1 is the first term and r is the common ratio.
The sum of the terms of a geometric sequence can be calculated using the formula S = (a1 * (r^n - 1))/(r - 1), where S is the sum, a1 is the first term, r is the common ratio, and n is the number of terms.