Arithmetic Sequence A number sequence a1 , a2 , a3,...,an is called an arithmetic sequence or arithmetic progression (A.P.) if there is a constant difference between each of the successive terms, i.e. a, a + d, a + 2d, a + 3d, a + 4d.... ‘d is called the common difference.
Geometric Sequence A number sequence is called a geometric sequence or geometric progression (G.P.), if each term is found by multiplying the previous one by the same constant (called common ratio) : a, ar, ar2, ar3, ar4,… r ≠ 0 is the common ratio.
Learnhive Lesson on Arithematic Progression