What Are the Kissing Numbers for Different Sized Spheres in 3D?

[jal]

I am looking for info on kissing numbers.
If all the spheres are of one unit then there are 12 spheres in 3d that can kiss the center sphere.
Question:
If the outer spheres are smaller by say 1/4, 1/2 etc. what would be the kissing numbers?
I assume that this has already been done but my search has not found anything.
jal

 

[maze]

The reason it works out nice for spheres of equal size is because the dodecahedron has 12 faces. I think the answer is going to be ugly for sphere kissings that don't correspond to platonic solids.