A geometric sequence is a list of numbers where each term is obtained by multiplying the previous term by a constant, often denoted r.
To find the sum of a given geometric sequence as well as the nth term in the sequence, simply fill in the necessary values below and then click the “Calculate” button.
a5 (the value of the 5th term) = 405
s5 (the sum of the first 5 terms) = 605
an (the value of the nth term) = a1 * rn-1
sn (the sum of the first n terms) = a1 * (1 – rn) / (1 – r)