Answer:
a_{n} = a_{1} + (n-1)d
a_n = the nᵗʰ term in the sequence
a_1 = the first term in the sequence
d = the common difference between terms
The general term of an arithmetic sequence can be written in terms of its first term a1, common difference d, and index n as follows: an=a1+(n−1)d. ... The nth partial sum of an arithmetic sequence can be calculated using the first and last terms as follows: Sn=n(a1+an)2.