Parent Category: calculators Category: Math Calculators Print Email Sum of Arithmetic Progression Calculator The Calculator helps calculating the Sum of Arithmetic Progression In mathematics, an arithmetic progression or arithmetic sequence is a sequence of numbers such that the difference between the consecutive terms is constant. For instance, the sequence 5, 7, 9, 11, 13, 15, . . . is an arithmetic progression with common difference of 2. The sum of Arithmetic Progression is equal to: Sn = n(a1 + an)/2 Where: a1 is the first term of an arithmetic progression. an is the n-th term of an arithmetic progression. n is the number of terms in the arithmetic progression. Sn is the sum of n terms in the arithmetic progression. the first term of an arithmetic progression - a1 the n-th term of an arithmetic progression - an the number of terms in the arithmetic progression - n