q 4 − 3 q 3 + 5 q 2 − 6 q + 7 − 6 q + 5 q 2 − 3 q 3 + 1 q 4 {\displaystyle q^{4}-3q^{3}+5q^{2}-6q+7-{\frac {6}{q}}+{\frac {5}{q^{2}}}-{\frac {3}{q^{3}}}+{\frac {1}{q^{4}}}}
