The Trefoil Knot

The trefoil knot is the simplest of the simple closed curves in 3-space. Here is the code for the above picture.

trefoil = {Sin[3t],Sin[t]+2Sin[2t],Cos[t]-2Cos[2t]};
TubePlotFrenet[trefoil, {t, 0, 2*Pi}, 0.3, Axes -> None,
    Boxed -> False, ViewPoint -> {10, 0, 0}, PlotPoints -> {64, 16},
    PlotLabel -> "The Trefoil Knot",
    LightSources->{{{1.,0.,1.}, RGBColor[1,0,0]},{{1.,1.,1.},
    RGBColor[0,1,0]},{{0.,1.,1.},RGBColor[0,0,1]},
    {{-1.,0.,-1.},RGBColor[1,0,0]},{{-1.,-1.,-1.},
    RGBColor[0,1,0]},{{0.,-1.,-1.},RGBColor[0,0,1]}}]