This online Arithmetic Sequence Calculator is used to calculate the nth term and the sum of the first n terms of arithmetic sequence.

In mathematics, an arithmetic sequence, also known as an arithmetic progression, is a sequence of numbers such that the difference of any two successive members of the sequence is a constant. The sum of the members of a finite arithmetic progression is called an arithmetic series.

If the initial term of an arithmetic sequence is a_{1} and the common difference of successive members is *d*, then the nth term of the sequence is given by:

a_{n} = a_{1} + (n - 1)d

The sum of the first n terms S_{n} of arithmetic sequence is calculated by the following formula:

S_{n} = n(a_{1} + a_{n})/2 = n[2a_{1} + (n - 1)d]/2