An arithmetic progression (AP) is a sequence of numbers in which each succeeding number is obtained either by adding or subtracting a specific number called the common difference.
The general form of AP is: , where is the common difference.
Geometric Progression:
A geometric progression (GP) is a sequence of numbers in which each succeeding number is obtained by multiplying a specific number called the common ratio.
The general form of GP is: , where is the common ratio.
Harmonic Progression:
A sequence of numbers is said to be a harmonic progression if the reciprocal of those numbers are in AP.