I have a tattoo that is the first 5 curves in the series that approaches a square wave. I chose this because 1) it looks cool, and 2) computers have been a substantial part of my life and the idea of the clock cycles passing from my body to the machine is neat. The reason it's the sine series is that a real microchip clock composes multiple sine waves from oscillating piezoelectric crystals to produce the square wave clock signal. I chose a count of 5 because it is a good balance between producing a usefully square wave and having so many curves that they obscure each-other.
Here is an interactive visualization of how different numbers of curves in the series approach an increasingly precise square wave. The first row of curves summed equals the lower curve.