Outputting a frame for every 10 frames

Outputting a frame for every 10 frames:
Source: https://superuser.com/questions/391257/extracting-one-of-every-10-frames-in-a-video-using-vlc-or-ffmpeg?rq=1
>>> ffmpeg -i "[Erai-raws] One Piece - 1089 [1080p][D7FDCDC3].mkv" -vf "select=not(mod(n\,10))" -vsync vfr -q:v 2 img_%03d.jpg

6 frames:
ffmpeg -i "[Erai-raws] One Piece - 1089 [1080p][D7FDCDC3].mkv" -vf "select=not(mod(n\,6))" -vsync vfr -q:v 2 img_%03d.jpg

16 frames:
ffmpeg -i "[Erai-raws] One Piece - 1089 [1080p][D7FDCDC3].mkv" -vf "select=not(mod(n\,16))" -vsync vfr -q:v 2 img_%03d.jpg