Composites are sums of prime steps

The torus, cut open. Every integer n sits at (log₂ n, depth Ω(n)). A prime is one step of (log₂ p, 1); a composite is where a chain of steps lands. Reorder the steps (dashed) and you land on the same point.

p = 2
p = 3
p = 5
p = 7
p = 11
p = 13
p ≥ 17
other composite
1 2 4 8 16 32 64 128 0 1 2 3 4 5 6 7 n, spaced by log₂ n: around the hole (φ) depth Ω(n): through the tube (θ) depth 3.5: the pinch. φ is erased here (0) {{t.t}} {{t.t}} {{final.t}}
{{nVal}}
{{f.text}}{{f.sep}}
{{kind}}
steplands onlog₂ ndepth
{{r.step}} {{r.lands}} {{r.lg}} {{r.dep}}
{{logLine}}
{{depthLine}}
The same route on the torus
0 {{tfinal.t}}
{{torusCaption}}
Center: the horn torus pinches shut at depth 3.5. Every helix (faint lines) crosses it whatever its φ, and no integer lands there.