How to create increasing space between objects in After Effects

Name the first layer "First Layer" and then add an Expression Control Slider named Exponent to the first layer.

Add this expression to every layer below the "First Layer."

ofst = thisComp.layer("First Layer").effect("Exponent")("Slider")/10;
ref = thisComp.layer(index - 1).position;
e = index * Math.exp(ofst);
[ref[0] + e, ref[1]];

The slider lets you adjust the distance between the layers. This is what you get:

Could be as simple as tying a Math.pow() or Math.exp() expression to the X position. It's just  ot really clear what the values are supposed to be.

Mylenium