q 12 − 4 q 11 + 8 q 10 − 13 q 9 + 16 q 8 − 18 q 7 + 18 q 6 − 14 q 5 + 10 q 4 − 5 q 3 + 2 q 2 {\displaystyle q^{12}-4q^{11}+8q^{10}-13q^{9}+16q^{8}-18q^{7}+18q^{6}-14q^{5}+10q^{4}-5q^{3}+2q^{2}}