− q 13 / 2 + 4 q 11 / 2 − 8 q 9 / 2 + 13 q 7 / 2 − 18 q 5 / 2 + 20 q 3 / 2 − 21 q + 17 q − 13 q 3 / 2 + 8 q 5 / 2 − 4 q 7 / 2 + 1 q 9 / 2 {\displaystyle -q^{13/2}+4q^{11/2}-8q^{9/2}+13q^{7/2}-18q^{5/2}+20q^{3/2}-21{\sqrt {q}}+{\frac {17}{\sqrt {q}}}-{\frac {13}{q^{3/2}}}+{\frac {8}{q^{5/2}}}-{\frac {4}{q^{7/2}}}+{\frac {1}{q^{9/2}}}}
