An algebraic sequence is a set of numbers where each term has a constant difference from the last. The constant difference is also called a common difference, and is referred to using the variable d. ^[1][2]

Some algebraic sequences use more than just one difference. Each difference uses a different name, such as a first difference, second difference, and third difference. An example of a multi-difference sequence are Quadratic sequences. Quadratic sequences have a first difference that changes, but a second difference that does not change. A common example of a quadratic sequence is a square sequence, where each term is a new square number.

1. ↑ "Client Challenge". www.khanacademy.org. Retrieved 2026-04-09.
2. ↑ "Sequences". www.mathsisfun.com. Archived from the original on 2020-08-12. Retrieved 2020-08-17.