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