q 21 / 2 − 2 q 19 / 2 + 5 q 17 / 2 − 9 q 15 / 2 + 13 q 13 / 2 − 15 q 11 / 2 + 15 q 9 / 2 − 15 q 7 / 2 + 10 q 5 / 2 − 7 q 3 / 2 + 3 q − 1 q {\displaystyle q^{21/2}-2q^{19/2}+5q^{17/2}-9q^{15/2}+13q^{13/2}-15q^{11/2}+15q^{9/2}-15q^{7/2}+10q^{5/2}-7q^{3/2}+3{\sqrt {q}}-{\frac {1}{\sqrt {q}}}}
