Flavor Mixing Parameters from Generation Hierarchy: An Empirical Observation

We report an empirical observation: the nine flavor mixing parameters of the Standard Model can be expressed as simple rational fractions constructed from powers of 3 and the integer 13. The generation hierarchy rule p_i = 3^(i-1), combined with the cluster number 13, reproduces all nine parameters with deviations below 2% from PDG 2024 values. Cross-relations between the quark and lepton sectors emerge from the structure. v2.0: Added preliminary JUNO result (sin²θ₁₂ = 0.3092 ± 0.0087, deviation 0.17σ from prediction 4/13 — first a priori test), explicit octant prediction for θ₂₃ (second octant required), RG running analysis for Weinberg angle (Q* ≈ 83.5 GeV), null model discussion, and updated NuFIT to 6.0. No changes to predictions or formulas.