Data:L9a30/HOMFLYPT Polynomial

$a^7 \left(-z^3\right)-2 a^7 z+a^5 z^5+3 a^5 z^3+2 a^5 z+a^3 z^5+3 a^3 z^3+2 a^3 z+a^3 z^{-1} -a z^3-3 a z-a z^{-1}$