ABACABAC

ABACABAC is a finite letter sequence consisting of the letters A, B, and C arranged as ABACABAC. In plain terms, it is the 8-character string formed by repeating the four-letter block ABAC twice.

Construction and form: The pattern can be generated by concatenating the base sequence ABAC with itself, yielding ABACABAC. It can also be described succinctly as the repetition (ABAC){2} and is a simple example of a periodic word on a three-letter alphabet.

Properties: ABACABAC has length 8. The letter counts are A = 4, B = 2, and C = 2. The sequence exhibits a basic form of periodicity with a repeating block of length 4, making it easy to recognize by string-processing methods. It is not a palindrome, since reversing it yields CABACABA.

Context and use: In discussions of pattern repetition, ABACABAC serves as a straightforward case for illustrating concepts in formal languages, automata theory, and string algorithms. It is often used as a low-complexity example when teaching how to detect repetition, compute periods, or test pattern-matching routines.

Relation to related ideas: ABACABAC is distinct from the ABACABA pattern, which is recursive and self-similar. While ABACABAC is two copies of ABAC, ABACABA builds a longer, more intricate sequence through iterative augmentation. See also ABAC, ABACABA, and repetition in formal language theory.