"The first known mention of the geometric series is due to Mahavira (850 CE) in his Ganitasarasangraha (ii.93): पदमितगुणहतिगुणितप्रभवस््स्ययाद्णगु धनं तदाद्यूनम।् एकोनगुणविभक्तं गुणसङ्कलितं विजानीयात्॥ which translates to The first term when multiplied by the continued product of the common ratio, taken as many times as the number of terms, gives rise to the gunadhana [the (n+1)th term of the geometric progression]. And it has to be understood that this gunadhana, when diminished by the first term and then divided by the common ratio lessened by one, becomes the sum of the series in the geometric progression."