a 4 z 8 + a 2 z 8 − a 6 z 6 + 6 a 4 z 6 + 6 a 2 z 6 − z 6 − 5 a 6 z 4 + 12 a 4 z 4 + 11 a 2 z 4 − 5 z 4 − 7 a 6 z 2 + 11 a 4 z 2 + 7 a 2 z 2 − 6 z 2 − 3 a 6 + 4 a 4 + a 2 − 1 {\displaystyle a^{4}z^{8}+a^{2}z^{8}-a^{6}z^{6}+6a^{4}z^{6}+6a^{2}z^{6}-z^{6}-5a^{6}z^{4}+12a^{4}z^{4}+11a^{2}z^{4}-5z^{4}-7a^{6}z^{2}+11a^{4}z^{2}+7a^{2}z^{2}-6z^{2}-3a^{6}+4a^{4}+a^{2}-1}
