Given any metric space $(X,d)$, define its score $S(X)$ to be the smallest value of $k$ such that for every $x\in X$ and $r>0$, the ball $B(x,r)$ is covered by at most $2^k$ balls of radius $r/2$.
What is the growth of $S(\mathbb{R}^n)$? I guess it's $\Theta(n)$?
($S(\mathbb{R})=1$, and I'm not sure about $S(\mathbb{R}^2)$.)