Figure 1.

Families of knots, with crossing sign assignment. (Top) Family of torus knots. (Middle) Family of twist knots with even crossing number. (Bottom) Family of twist knots with odd crossing number. Wr is the 3D writhe of the ideal configuration obtained by simulation. (Note that for each chiral knot, we chose the enantiomorph having a positive topological writhe. For all the knots represented in this figure, this enantiomorph corresponds to the mirror image of the enantiomorph usually presented in reference tables; ref. 7.)