  In "Dense Sphere Packings: A Blueprint for Formal Proofs" Hales proves that
for every packing of unit spheres, the density in a ball of radius $r$ is at
most $\pi/\sqrt{18}+c/r$ for some constant $c$. When $r$ tends to infinity,
this gives a proof to the famous Kepler conjecture. As formulated by Hales, $c$
depends on the packing. We follow the proofs of Hales to calculate a constant
$c'$ independent of the sphere packing that exists as mentioned in "A Formal
Proof of the Kepler Conjecture" by Hales et al..
