q 13 / 2 − q 11 / 2 + q 9 / 2 − 2 q 7 / 2 + q 5 / 2 − q 3 / 2 − 1 q {\displaystyle q^{13/2}-q^{11/2}+q^{9/2}-2q^{7/2}+q^{5/2}-q^{3/2}-{\frac {1}{\sqrt {q}}}}
