Is there a mathematical formula to determine how much XP is needed per level?

I originally thought it was the previous amount times 2, but that doesn't work for all levels.

I understand that there is a character advancement table, but I'm curious as to how they got those numbers and whether there is some mathematical formula to work it out.

Is there a mathematical formula to determine how much XP is needed per level? In other words Is there a consistent formula for determining how much XP is needed to go up to any given level?

I originally thought it was the previous amount times 2, but that doesn't work for all levels.

I understand that there is a character advancement table, but I'm curious as to how they got those numbers and whether there is some mathematical formula to work it out.

Is there a mathematical formula to determine how much XP is needed per level? I originally though it was the previous amount time 2 but that doesn't work for all of them. I understand that there is a list but I'm curious as to how they got those numbers and if there is some mathematical formula to work it out.

Is there a mathematical formula to determine how much XP is needed per level? 

I originally thought it was the previous amount times 2, but that doesn't work for all levels. 

I understand that there is a character advancement table, but I'm curious as to how they got those numbers and whether there is some mathematical formula to work it out.

Is there a mathematical question to determine How much XP is needed per level? I originally though it was the previous amount time 2 but that doesn't work for all of them. I understand that there is a list but I'm curious as to how they got those numbers and if there is some mathematical formula to work it out.

Is there a mathematical formula to determine how much XP is needed per level? I originally though it was the previous amount time 2 but that doesn't work for all of them. I understand that there is a list but I'm curious as to how they got those numbers and if there is some mathematical formula to work it out.