− q 13 / 2 + q 11 / 2 − 4 q 9 / 2 + q 7 / 2 − 4 q 5 / 2 + 2 q 3 / 2 − 3 q {\displaystyle -q^{13/2}+q^{11/2}-4q^{9/2}+q^{7/2}-4q^{5/2}+2q^{3/2}-3{\sqrt {q}}}
