[arch-general] list of user/group ids supplied by official packages

Is there a list of user/group IDs that official packages from [core] [extra] and [community] provide? I wish to insure that the user/group id in an AUR package I provide[1] does not conflict a user created by an official package. I can grep for 'useradd' in my abs tree and parse through the resulting 137 lines but there must be a better way. Thanks. 1. https://aur.archlinux.org/packages/kodi-standalone-service