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