q 15 − 2 q 14 + 3 q 13 − 5 q 12 + 4 q 11 − 4 q 10 + 3 q 9 − q 8 + 2 q 6 − q 5 + q 4 {\displaystyle q^{15}-2q^{14}+3q^{13}-5q^{12}+4q^{11}-4q^{10}+3q^{9}-q^{8}+2q^{6}-q^{5}+q^{4}}
