How to compare limits for creating new objects in world space?

Maybe it's a little bit unreal but I try. I'm a Houdini artist and now I need to create AR application with cell division animation. For this I want to compare all limits where new cell shoud be. Then move cell to this position, crate new one when position is reached, add new limits (based on created cell) and repeat operation. For visual example I draw the image:

Pink zones is where new targetPosition never must be. Green line it's a desired postion for new targetPosition. Blue ones are the spheres

For third cell in a row desired position (Green line):

The main question is: How can I compare, add and store all Vector3 limits that can be created? Thank, If somebody somehow really understand what I mean :) P.S.: If it's possible for Vector2 is ok too.