q 21 / 2 − 4 q 19 / 2 + 8 q 17 / 2 − 12 q 15 / 2 + 16 q 13 / 2 − 18 q 11 / 2 + 17 q 9 / 2 − 15 q 7 / 2 + 10 q 5 / 2 − 6 q 3 / 2 + 2 q − 1 q {\displaystyle q^{21/2}-4q^{19/2}+8q^{17/2}-12q^{15/2}+16q^{13/2}-18q^{11/2}+17q^{9/2}-15q^{7/2}+10q^{5/2}-6q^{3/2}+2{\sqrt {q}}-{\frac {1}{\sqrt {q}}}}
