 Centered octagonal number

A centered octagonal number is a type of figurate number that represents a pattern of dots arranged in an octagonal shape. The formula to find the nth centered octagonal number is given by: \[ C_n = 3n^2 - 3n + 1 \] where \(C_n\) is the nth centered octagonal number and \(n\) is a positive integer (1, 2, 3, ...).