q 11 / 2 − q 9 / 2 + q 7 / 2 − q 5 / 2 + q 3 / 2 − q − 1 q − 1 q 5 / 2 {\displaystyle q^{11/2}-q^{9/2}+q^{7/2}-q^{5/2}+q^{3/2}-{\sqrt {q}}-{\frac {1}{\sqrt {q}}}-{\frac {1}{q^{5/2}}}}