  Let $\bar{S}$ denote the set of integers $n$ such that $n!$ cannot be written
as a sum of three squares. Let $\bar{S}(n)$ denote $\bar{S} \cap [1, n]$. We
establish an exact formula for $\bar{S}(2^k)$ and show that $\bar{S}(n) = 1/8*n
+ \mathcal{O}(\sqrt{n})$. We also list the lengths of gaps appearing in
$\bar{S}$. We make use of the software package Walnut to establish these
results.
