5th dnd – What is the formula behind every advance of slot machine?

I've tried to find a way to find the formula behind the progression of the slot slot on the multi-class roulette table, to add a slot table of spells to this sheet, the best example being that of the last group of tables at the end of the second page. seems to be a trend, but I can not find the formula. Especially because a lot of lower level sites are limited to a number around 3 after only a few levels.

I've been linked to this message a few times because it has a similar title to my question, but it does not have the answer I'm looking for. If anyone has the formula for individual level niche progression per level, this would be greatly appreciated.

What is the formula that can be used to generate the spell locations for each level of the multi-cast spell location table?