1 q 2 − 1 q 3 + 3 q 4 − 3 q 5 + 3 q 6 − 3 q 7 + 2 q 8 − 1 q 9 {\displaystyle {\frac {1}{q^{2}}}-{\frac {1}{q^{3}}}+{\frac {3}{q^{4}}}-{\frac {3}{q^{5}}}+{\frac {3}{q^{6}}}-{\frac {3}{q^{7}}}+{\frac {2}{q^{8}}}-{\frac {1}{q^{9}}}}