text: what is the formula for the sum of an arithmetic series? this is the sequence i am working with  2,4,6,8,10 fortunately, there is a simple formula for finding the sum of an arithmetic series.   in general, the sum of an arithmetic series can be written as follows:   s = i + (i+d) + (i+2d) + (i+3d) + ... +[i+(n-1)d]  and can be simplified as:   s = (n / 2) * [2i + (n-1) * d]   where i is the initial term, d is the difference between successive terms and n is the number of terms in the series.