Data:L11n270/HOMFLYPT Polynomial

$2 z^6-3 a^2 z^4-2 z^4 a^{-2} +12 z^4+a^4 z^2-14 a^2 z^2-8 z^2 a^{-2} +24 z^2+4 a^4-18 a^2-7 a^{-2} +21+3 a^4 z^{-2} -8 a^2 z^{-2} -2 a^{-2} z^{-2} +7 z^{-2}$