(How) is it possible to create a recurring calendar event where each occurrence has an iterated number?
Not sure, webdav itself does provide such a feature to iterate over e.g. birthdays? Or is it always the application? As far as I know, a recurring event is just one entry, that just says it repeats every xx time. But there is only one name to it.
I think it’s the client application that generates multiple events, which are then somehow linked together in the back end. I don’t know the inner workings of it, but since it is possible to delete individual events in a series, it should theoretically be possible to implement what @vatolin wants…
…unless for some reason the events in a series need to have the same title in order to be linked together. But even if that were the case, it should theoretically be possible for a client application to generate a series of unlinked events with different titles. I just haven’t come across a client application that does this, which of course doesn’t mean that such an application doesn’t exist 
and since we have caldav, it should be possible to do this in a small script…
Could somebody please give an example how to code such a script? Or could this made by an AI?