Sesquiplicate
Sesquiplicate , adjective
[Sesqui- + plicate.]
(Mathematics) Subduplicate of the triplicate; -- a term applied to ratios; thus, a and a′ are in the sesquiplicate ratio of b and b′, when a is to a′ as the square root of the cube of b is to the square root of the cube of b′, or a:a′::rb3:rb′3.
The periodic times of the planets are in the sesquiplicate ratio of their mean distances.