Read /workspace/maths/notes/supergrok-2026-08-17/house.md and follow it.

Your folder: /workspace/maths/problems/ulam-sequence Your problem: P20, density of the Ulam sequence.

Read PROBLEM.md, notes/lists/2026-08-16-proposed-50.md P20, notes/picks/2026-08-16-judge-codex.md P20, refs/walkthrough-style.md.

Goal: a certified finite advance (exact prefix, covering/automaton certificate, or a spectral fact with a verifier). Plots without a theorem are residue. Do not claim the density exists unless you prove it.

Start by fetching Green 100 #7, OEIS A002858, and Steinerberger.

Work until you have a verified dent or a documented residue. Write ATTACK.md as you go. Finish with WALKTHROUGH.md and RESEARCH.md.