geometric progression
noun /ˌdʒiːəˌmetrɪk prəˈɡreʃn/
/ˌdʒiːəˌmetrɪk prəˈɡreʃn/
(also geometric series)
(mathematics- a series of numbers in which each is multiplied or divided by a fixed number to produce the next, for example 1, 3, 9, 27, 81
compare arithmetic progression几何数列;等比数列