Data:10 99/HOMFLYPT Polynomial

$z^8-a^2 z^6-z^6 a^{-2} +6 z^6-4 a^2 z^4-4 z^4 a^{-2} +14 z^4-6 a^2 z^2-6 z^2 a^{-2} +16 z^2-4 a^2-4 a^{-2} +9$