Data:L9n2/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 a^7 (-z)-a^7 z^{-1} +a^5 z^3+2 a^5 z+2 a^5 z^{-1} +a^3 z^3+a^3 z-2 a z-a z^{-1} }