Geometric progression or sequence, is a sequence of numbers where each term after the first is found by multiplying the previous one by a fixed nonzero number called the common ratio. For example, the series 2, 6, 18, 54, ... is a geometric progression with common ratio 3.
Formula:
Gp = a r ^{(n1)
}Where,
a  first term in the series,
n  last term in the series,
r  common difference.
