A constant sequence is a type of mathematical sequence where every term is the same. For example, in the sequence 5, 5, 5, 5, each term is equal to 5. This means that no matter how many terms you have, they will all be identical. Constant sequences can be represented mathematically as a, a, a, a, where "a" is any fixed number. In terms of notation, a constant sequence can be expressed as a_n = a for all n, where "n" represents the position of the term in the sequence. Constant sequences are a simple yet important concept in mathematics, particularly in the study of limits and series.