A bonus of 30 xp per gen isn't exponential growth. It is linear growth. Oh for fuck's sake, studying math and browsing the internet simultaneously makes me an annoying wise ass on this forum and sloppy at math.
Please do us a favor don't talk about math ever.
The rate your xp grow is proportional to how much gen you have , so proportional to how much xp you got since the begining.
Y'=ay
What kind of fuckin differiential equation is that?