Punctured affine three-space (${\mathbb{A}}_k^3\setminus \{0\}$)

For $U={\mathbb{A}}_k^3\setminus \{0\}$,andThe last group has basis represented by $x_1^{-a}{x}_2^{-b}{x}_3^{-c}$ for $a,b,c\ge 1$, and all groups in degrees at least three vanish.