Gallardo’s irreducibility equivalence for binary all-ones polynomials

Over F₂, is 1+X+⋯+Xⁿ irreducible exactly when its composition with X²+X+1 is irreducible, for every n≥2? The excluded case n=1 does not obey the same formulation.

Why it matters and what counts as progress

Why it matters: The equivalence connects a sparse algebraic substitution with irreducibility of a familiar binary polynomial family.

What counts as progress: Prove the equivalence using a composition criterion, formalize both directions or classify analogous substitutions.

How the problem developed

  1. 23 Dec 2019 · Conjecture [1]

    Luis H. Gallardo Conjectured that for n≥2, the binary all-ones polynomial is irreducible exactly when the corresponding polynomial in X²+X+1 is irreducible.

  2. 11 Sept 2026 · Formalized result [2][3]

    GPT-6 Astra, Claude Fable 5.1, and Claude Opus agents, with Brandon Yates selecting and reviewing the target A Lean-verified record gives the per-n equivalence for n≥2 and the corresponding sequence statement, excluding n=1; the proof uses a classical trace criterion.

AI contribution

Sources

  1. OEIS A071642, Gallardo’s conjecture
  2. AIProofWatch, AI proof of Gallardo’s all-ones polynomial equivalence
  3. Palomar registry, Lean-verified Gallardo equivalence record
  4. Yates, all-ones polynomial proof and verification
Website timeline

Publication dates and editorial changes.