Assistance in creating a specific structure

(Mac-Version User) I'm trying to create a structure/feature called "spawn crater", yet I'm having trouble visualizing it in code.

Idea: At the Coordinates (0,0,0), every block within the first four chunks above 0,0,0 would be turned to air. The next set of chunks would be replaced with air the next step up. It would do this until it reached sea level. The equivalent in Minecraft would be:

/fill -(X*16) (0<X≤62) -(X*16) (X*16) 320 (X*16) air

Example:

/fill -0 0 -0 0 320 0 air: ERROR-Task Unexecuted

/fill -1008 63 -1008 1008 320 1008 air: ERROR-Task Unexecuted

/fill -800 50 800 800 320 800 air: Success