Sweep for the arms, Nsided (with some temporary vertical extrusions built in between the arms to do NSided between) for the central hub, then some trimming and blends to improve the arm/hub transition a bit.

- Michael

I came across "polyskelion," "pentaskelion," and found some equations.

Lots of examples: http://benice-equation.blogspot.com/

Equations: http://math.stackexchange.com/questions/651772/parametric-equations-and-specifications-of-a-triskelion-triple-spiral

Will try to do a script...

- Brian