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