<< KnotTheory`

LeadCoef[K_] := Coefficient[j=Jones[K][q], q, Exponent[j, q]]

LeadCoef[Knot[3,1]]

Select[AllKnots[{3,13}], Abs[LeadCoef[#]] > 2&]

Select[AllKnots[{3,13}], Abs[LeadCoef[#]] > 3&]