− q 7 / 2 + 4 q 5 / 2 − 8 q 3 / 2 + 13 q − 18 q + 20 q 3 / 2 − 20 q 5 / 2 + 16 q 7 / 2 − 13 q 9 / 2 + 7 q 11 / 2 − 3 q 13 / 2 + 1 q 15 / 2 {\displaystyle -q^{7/2}+4q^{5/2}-8q^{3/2}+13{\sqrt {q}}-{\frac {18}{\sqrt {q}}}+{\frac {20}{q^{3/2}}}-{\frac {20}{q^{5/2}}}+{\frac {16}{q^{7/2}}}-{\frac {13}{q^{9/2}}}+{\frac {7}{q^{11/2}}}-{\frac {3}{q^{13/2}}}+{\frac {1}{q^{15/2}}}}
