q 13 − 4 q 12 + 6 q 11 − 9 q 10 + 11 q 9 − 11 q 8 + 10 q 7 − 7 q 6 + 5 q 5 − 2 q 4 + q 3 {\displaystyle q^{13}-4q^{12}+6q^{11}-9q^{10}+11q^{9}-11q^{8}+10q^{7}-7q^{6}+5q^{5}-2q^{4}+q^{3}}