− z 6 + a 2 z 4 + z 4 a 2 − 5 z 4 + 3 a 2 z 2 + 3 z 2 a 2 − 8 z 2 + 2 a 2 + 2 a 2 − 3 {\displaystyle -z^{6}+a^{2}z^{4}+{\frac {z^{4}}{a^{2}}}-5z^{4}+3a^{2}z^{2}+{\frac {3z^{2}}{a^{2}}}-8z^{2}+2a^{2}+{\frac {2}{a^{2}}}-3}
