259.lean`

Explanation legend Lean4 Domain Explanation Language (L4DEL)

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L4DEL: Lean4 Domain Explanation Language

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Credit: The upstream authors and contributors retain credit for the project and mathematics. lean4-explainer only renders their pinned source and adds the separately disclosed explanation layer.

Project sources: Pinned project documentation, Formal Conjectures paper, arXiv v1

1 declarations, 1 contain sorry, 0 declared as axioms

Erdős Problem 259

Reference: erdosproblems.com/259

Imports (1)

FormalConjecturesUtil

theorem Erdos259.erdos_259 Is $\sum_{n} \mu(n)^2\frac{n}{2^n}$ irrational? sorry line 40 source
Source documentation
Is $\sum_{n} \mu(n)^2\frac{n}{2^n}$ irrational?
This is true, and was proved by Chen and Ruzsa.
[ChRu99] Chen, Yong-Gao and Ruzsa, Imre Z., On the irrationality of certain series. Period. Math. Hungar. (1999), 31--37.

depends on sorry what this means
Statement uses: Irrational, tsum, Real, Nat, HDiv.hDiv, HMul.hMul, HPow.hPow, ArithmeticFunction, Int, ArithmeticFunction.moebius, OfNat.ofNat, SummationFilter.unconditional
Proof uses: sorryAx, Lean.Name, Bool.false, Lean.Name.num, Lean.Name.str, Lean.Name.anonymous
52 instances, coercions and auxiliary constants left out.

Tactic trace: 1 steps
Open to load the checked before-and-after goal states.
```
theorem erdos_259 : Irrational (∑' n : ℕ, (μ n) ^ 2 * n / (2 ^ n)) := by
…
```