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