The start frame range is one frame longer than the number of frames (image attached).

Repro steps:
1. Open Test scene from attached project.
2. Select particle system and scroll to the Texture Sheet Animation module.
3. Observe how the start frame range starts at 0 and goes up to tiles XY (i.e. frame 0 and frame XY are the same frame).

Notes:
- not a regression, has always been like this.