q 30 − q 28 − 2 q 22 + q 20 − 2 q 18 + q 16 + q 14 + 3 q 10 − q 8 + q 6 + 1 {\displaystyle q^{30}-q^{28}-2q^{22}+q^{20}-2q^{18}+q^{16}+q^{14}+3q^{10}-q^{8}+q^{6}+1}