<< KnotTheory`

L=Link["L7a6"];

H=HOMFLYPT[PD[L]][a,z]

{HOMFLYPT[Mirror[L]][a,z], H /. a-> -1/a}

U3=PD[Mirror[BR[3,{1,-1,2,-2,1,-1,2,-2}]]]

DrawMorseLink[U3]

HOMFLYPT[U3][a,z] // Simplify

l[L_] := Series[HOMFLYPT[L][E^(n x), E^x-1/E^x], {x,0,1}]

l[BR[2,{1,1,1,1,1,1}]]

l[BR[2,{1,-1,1,-1,1,-1}]]

l[BR[2,{1,-1,1,-1,1,-1, 1}]]

l[L]

DrawMorseLink[BR[2,{1,1,1,1,1,1}]]

BR[Knot[3,1]]

DrawMorseLink[BR[Knot[3,1]]]