Stupid question. I want to randomize curtain panels in %50 %50 selected family types. But not random. Type A should be next to B and after B there should be again type A.
It isn’t a stupid question 
It might be that this link is useful to you…
https://forum.dynamobim.com/t/random-list-and-adjacent-families/21345/28
Personally, I would manually create a pattern which looks random, and repeat that as many times as necessary, chopping it at the edges.
Best of luck,
Mark