Here is my sentence: I'm trying to say that "The gods seemed to favor Romulus because he saw 12 vultures, twice the number of birds that Remus saw."
Dii Romulō favere visi sunt quia ille duodecim vultures vidit, duplicem numerum avium quem Remus viderat.
I'm not sure about the "quem" here and if that part of the sentence makes sense. Thanks!