In mathematics, an **arithmetic progression** (AP) or arithmetic sequence is a sequence of numbers such that the difference between the consecutive terms is constant. For instance, the sequence 5, 7, 9, 11, 13, 15 etc. is an **arithmetic progression** with common difference of 2. Wikipedia, Arithmetical Progression

See Also

**Cause and Its Effects**
**Geometrical Progression**
**progression**
**12.18 - Multiple Octave Progression**