Data:10 28/HOMFLYPT Polynomial

Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle 2 z^4 a^{-2} +z^4 a^{-4} +z^4-a^2 z^2+4 z^2 a^{-2} +z^2 a^{-4} -z^2 a^{-6} +3 a^{-2} - a^{-6} -1}