Standalone 4-page LaTeX note in notes/menagerie.tex with figures
generated by notes/generate_figures.py, summarizing edge 3-coloring
counts for the menagerie of subcubic outerplanar graphs:
- Path P_n: P_e(P_n, 3) = 3 · 2^{n-2}.
- Cycle C_n: P_e(C_n, 3) = 2^n + 2(-1)^n.
- Star K_{1,3}: P_e = 6.
- Corona C_n ∘ K_1: same as C_n (leaves are forced).
- Trees with Δ ≤ 3: product over BFS-order via greedy.
- 2-connected blocks: just cycles (chords force Δ > 3 generically).
- Block-cut tree decomposition for general subcubic outerplanar.
- Outside the menagerie: theta(2,2,2) = K_{2,3} (not outerplanar),
which is the interior-dual structure of D(T) when O has a bridge.
The note is meant as a quick reference for the partial-tire-dual
paper, particularly for the spoke-only case (corona) and as
motivation for the theta-graph carve-out in the bridge case.
6 small PNG figures included.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
didericis
c599975290