− q 7 / 2 + 3 q 5 / 2 − 7 q 3 / 2 + 12 q − 18 q + 20 q 3 / 2 − 21 q 5 / 2 + 18 q 7 / 2 − 14 q 9 / 2 + 9 q 11 / 2 − 4 q 13 / 2 + 1 q 15 / 2 {\displaystyle -q^{7/2}+3q^{5/2}-7q^{3/2}+12{\sqrt {q}}-{\frac {18}{\sqrt {q}}}+{\frac {20}{q^{3/2}}}-{\frac {21}{q^{5/2}}}+{\frac {18}{q^{7/2}}}-{\frac {14}{q^{9/2}}}+{\frac {9}{q^{11/2}}}-{\frac {4}{q^{13/2}}}+{\frac {1}{q^{15/2}}}}
