PDF Arithmetic Sequences & Series Worksheet ARITHMETIC SEQUENCES & SERIES WORKSHEET The general term of an arithmetic sequence is given by the formula a n = a 1 + (n - 1)d where a 1 is the first term in the sequence and d is the common difference. Finding the sum of a given arithmetic sequence: 1. Identify a 1, n, and d for the sequence. 2. Find a n using a n = a 1 + (n - 1)d. 3 ...