Wighted semi-random groups

I have a list of 100 objects.

I want to group these objects into sets of 4 - 12; I want to do this over and over again.

When these objects are grouped into sets I want it to be more likely that they are with other objects that they have not been grouped with.

I know I am going to need to have some type of structure to hold how many times each object has been grouped with each other object.

I'm sure this has been done before, but my searches are not coming up with anything and I probably just need the right term to search for.

What is the term I need to search for to find out more on how to do this efficiently? Good links on how to do this would be nice too.