Domain / Series with 0 in the middle

Hello all.

I don't have a script to share because what I'm trying to achieve is just in my head, but I can't figure out how to get it to work. Basically, I have 6 planar surfaces that I want to offset, but I want to offset them in a series of six values (lets say 8,4,0,4,8,12 to keep it simple). Essentially I want to create a "domain" that goes from 8 to 12 but by going negative down to 0 first before bouncing back up. I don't think I can use the construct domain component to achieve this and I don't know how to do it. 

Thanks in advance!

Ben

EDIT: I know I can easily accomplish this by plugging a multiline panel with the given values into the D input of Offset Surface, but I would like to be able to do it computationally so that if I change an input to 3, for example, it would adjust the series of numbers to be 6,3,0,3,6,9 or if I used 2, the adjustment would be 4,2,0,2,4,6. It doesn't have to be exactly this pattern but I am looking for a "bulge" in my offset surfaces with a 0 value in the middle.