− z 2 a 12 − a 12 + z 4 a 10 + z 2 a 10 + z 4 a 8 + z 2 a 8 + z 6 a 6 + 6 z 4 a 6 + 8 z 2 a 6 + 2 a 6 {\displaystyle -z^{2}a^{12}-a^{12}+z^{4}a^{10}+z^{2}a^{10}+z^{4}a^{8}+z^{2}a^{8}+z^{6}a^{6}+6z^{4}a^{6}+8z^{2}a^{6}+2a^{6}}
