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