I wouldn't think math is science. Otherwise, the acronym STEM (Science, Technology, Engineering, and Math) would be awfully redundant. And yeah, I'd say CS is closer to math than science, except maybe when you look at things like manufacturing processes and such, which is more of an engineering or materials science track.
Type systems, algorithm proof, complexity, boolean logic...
And if we go into CS applications: games are maths, bioinformatics is maths, accounting is maths, ...
Or in the implementation: electronics, semi-conductors physic, eletrical engineering, ...