How much influence does it take to level up?
Solution 1:
So far, at player level 150, it has taken a static 15,000 influence per level. I suspect this could increase after hitting level 200 and getting 1 star, where your level resets to level 1.
I received several pop up notifications in game that stated my total influence, which was always a multiple of 15,000. At level 101, the notification showed 1,500,000 total influence earned.
update I have since passed level 200, gaining the 1 star icon next to my name. It does seem to take more influence per level now, though I haven't been able to determine the exact amount yet.