− 1 q + 1 q 3 / 2 − 1 q 5 / 2 + 1 q 7 / 2 − 1 q 11 / 2 − 1 q 15 / 2 + 1 q 17 / 2 − 1 q 19 / 2 {\displaystyle -{\frac {1}{\sqrt {q}}}+{\frac {1}{q^{3/2}}}-{\frac {1}{q^{5/2}}}+{\frac {1}{q^{7/2}}}-{\frac {1}{q^{11/2}}}-{\frac {1}{q^{15/2}}}+{\frac {1}{q^{17/2}}}-{\frac {1}{q^{19/2}}}}
