2 a z 7 + 2 z 7 a + 4 a 2 z 6 + 4 z 6 a 2 + 8 z 6 + 3 a 3 z 5 + 2 a z 5 + 2 z 5 a + 3 z 5 a 3 + a 4 z 4 − 6 a 2 z 4 − 6 z 4 a 2 + z 4 a 4 − 14 z 4 − 4 a 3 z 3 − 6 a z 3 − 6 z 3 a − 4 z 3 a 3 − a 4 z 2 + 3 a 2 z 2 + 3 z 2 a 2 − z 2 a 4 + 8 z 2 + a 3 z + 2 a z + 2 z a + z a 3 − a 2 − 1 a 2 − 1 {\displaystyle 2az^{7}+{\frac {2z^{7}}{a}}+4a^{2}z^{6}+{\frac {4z^{6}}{a^{2}}}+8z^{6}+3a^{3}z^{5}+2az^{5}+{\frac {2z^{5}}{a}}+{\frac {3z^{5}}{a^{3}}}+a^{4}z^{4}-6a^{2}z^{4}-{\frac {6z^{4}}{a^{2}}}+{\frac {z^{4}}{a^{4}}}-14z^{4}-4a^{3}z^{3}-6az^{3}-{\frac {6z^{3}}{a}}-{\frac {4z^{3}}{a^{3}}}-a^{4}z^{2}+3a^{2}z^{2}+{\frac {3z^{2}}{a^{2}}}-{\frac {z^{2}}{a^{4}}}+8z^{2}+a^{3}z+2az+{\frac {2z}{a}}+{\frac {z}{a^{3}}}-a^{2}-{\frac {1}{a^{2}}}-1}
