3 a z 7 + 3 z 7 a + 6 a 2 z 6 + 6 z 6 a 2 + 12 z 6 + 4 a 3 z 5 + 3 a z 5 + 3 z 5 a + 4 z 5 a 3 + a 4 z 4 − 9 a 2 z 4 − 9 z 4 a 2 + z 4 a 4 − 20 z 4 − 4 a 3 z 3 − 9 a z 3 − 9 z 3 a − 4 z 3 a 3 + 3 a 2 z 2 + 3 z 2 a 2 + 6 z 2 + a z + z a + a 2 + 1 a 2 + 3 {\displaystyle 3az^{7}+{\frac {3z^{7}}{a}}+6a^{2}z^{6}+{\frac {6z^{6}}{a^{2}}}+12z^{6}+4a^{3}z^{5}+3az^{5}+{\frac {3z^{5}}{a}}+{\frac {4z^{5}}{a^{3}}}+a^{4}z^{4}-9a^{2}z^{4}-{\frac {9z^{4}}{a^{2}}}+{\frac {z^{4}}{a^{4}}}-20z^{4}-4a^{3}z^{3}-9az^{3}-{\frac {9z^{3}}{a}}-{\frac {4z^{3}}{a^{3}}}+3a^{2}z^{2}+{\frac {3z^{2}}{a^{2}}}+6z^{2}+az+{\frac {z}{a}}+a^{2}+{\frac {1}{a^{2}}}+3}
