Alright - here's my problem: I need to have a formula where when 0<X<11, it's multiplied by three. So 3X would simply be 9. Now it starts to get tricky. For every 10 after that, X is equal to the last value plus one. So 10X=30, but 11X=34. After another 10, X will equal 5 (21X=75), and then in another 10, it's worth 6.
The numbers are starting to eat my brains, and if I don't have a formula for this strange growth situation, I will lose the last little bit of my neurons. Thank you so much for your help.
Edit: The closest I've gotten so far is 2X+1/10X^2