Final A-B-C FLUTE

This object has reached its apex because:

The amount of positive space left adds interest to the negative space and gives it significance.
To keep subtracting would be to loose the effect because there would be nothing to show the shapes that have been taken away.

Run out of room to continue my sequence, it has been repeated as many times as is possible with my particular formula.

Satisfying to the eye, it appears to be finished.

You can recognise the shape it makes- a flute.

Although pieces have been taken out it still retains the appearance of being one object (rather than little pieces joined together).