[chaosmachine]

My best:

  tan(i*t/999)*(~~(t*24%7)==i%7)

https://doersino.github.io/tixyz/?code=tan%28i*t%2F999%29*%2...

Play with the frame rate ("24") for some interesting effects.

Edit: One more:

https://doersino.github.io/tixyz/?code=sin%28i*t%2F999%29*%2...