Line 1 show the exploding dice roll and line 2 the theorical curve with M = 0 and E = 3. The probability curve is express as fraction and errors in percentile.
The computation was done with results up to 5 rolls (results going from -50 to +50), with a precision of approximately 3 digits.
The relative peak at 100% at -20 is because of a null probability (the range of a limited roll being between -19 to +19).
The script is available here.