This symbol represents any given integer, \( k \in \htmlClass{sdt-0000000122}{\mathbb{Z}}\).
This symbol represents any given integer, \( k \in \htmlClass{sdt-0000000122}{\mathbb{Z}}\), meaning that \(n \:\:\: \text{is one of} \:\:\: ..., -2, -1, 0,1,2, ... \).
This symbol \( (k) \) represents any given integer, \( k \in \htmlClass{sdt-0000000122}{\mathbb{Z}}\), meaning that \(n \:\:\: \text{is one of} \:\:\: ..., -2, -1, 0,1,2, ... \). It is a very commonly used variable when expressing products or sums or anything where a variable can take on any integer.