z 18 + 17 z 16 + 119 z 14 + 442 z 12 + 936 z 10 + 1131 z 8 + 741 z 6 + 235 z 4 + 30 z 2 + 1 {\displaystyle z^{18}+17z^{16}+119z^{14}+442z^{12}+936z^{10}+1131z^{8}+741z^{6}+235z^{4}+30z^{2}+1}
