FormalConjectures/OEIS/87719.lean

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L4DEL
Lean4 Domain Explanation Language

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

8 declarations, 2 contain sorry, 0 declared as axioms

Conjectures associated with A087719

Define $\varsigma(n)$ the smallest prime factor of $n$ (Nat.minFac). Let $a_n$ be the least number such that the count of numbers $k \le a_n$ with $k > \varsigma(k)^n$ exceeds the count of numbers with $k \le \varsigma(k)^n$.

The conjecture states that $a_n = 3^n + 3 \cdot 2^n + 6$ for $n \ge 1$.

References:

Imports (1)
  1. def OeisA87719.countExceeding Count of numbers k in {1, ..., m} where k > (minFac k)^n line 40 source

    Source documentation

    Count of numbers k in {1, ..., m} where k > (minFac k)^n.

    standard axioms: Classical.choice, Quot.sound, propext what this means

    Statement uses: Nat

    Proof uses: Finset.card, Finset.filter, GT.gt, HPow.hPow, Nat.minFac, Finset.Icc, OfNat.ofNat

    9 instances, coercions and auxiliary constants left out.

    def countExceeding (n m : ℕ) : ℕ :=
    …
  2. def OeisA87719.countNotExceeding Count of numbers k in {1, ..., m} where k ≤ (minFac k)^n line 44 source

    Source documentation

    Count of numbers k in {1, ..., m} where k ≤ (minFac k)^n.

    standard axioms: Classical.choice, Quot.sound, propext what this means

    Statement uses: Nat

    Proof uses: Finset.card, Finset.filter, LE.le, HPow.hPow, Nat.minFac, Finset.Icc, OfNat.ofNat

    9 instances, coercions and auxiliary constants left out.

    def countNotExceeding (n m : ℕ) : ℕ :=
    …
  3. theorem OeisA87719.a_exists There exists m such that countExceeding n m > countNotExceeding n m sorry line 49 source

    Source documentation

    There exists m such that countExceeding n m > countNotExceeding n m.

    depends on sorry what this means

    Statement uses: Nat, Exists, GT.gt, OeisA87719.countExceeding, OeisA87719.countNotExceeding

    Proof uses: sorryAx, Lean.Name, Bool.false, Lean.Name.num, Lean.Name.str, Lean.Name.anonymous, OfNat.ofNat

    3 instances, coercions and auxiliary constants left out.

    Tactic trace: 1 steps

    Open to load the checked before-and-after goal states.

    theorem a_exists (n : ℕ) : ∃ m, countExceeding n m > countNotExceeding n m := by
    …

    Mentions: OeisA87719.countExceeding, OeisA87719.countNotExceeding

  4. def OeisA87719.a The sequence a(n): least m such that countExceeding n m > countNotExceeding n m line 53 source

    Source documentation

    The sequence a(n): least m such that countExceeding n m > countNotExceeding n m.

    depends on sorry what this means

    Statement uses: Nat

    Proof uses: Nat.find, GT.gt, OeisA87719.countExceeding, OeisA87719.countNotExceeding, OeisA87719.a_exists

    2 instances, coercions and auxiliary constants left out.

    noncomputable def a (n : ℕ) : ℕ :=
    …
  5. theorem OeisA87719.a_1 a(1) = 15 line 58 source

    Source documentation

    a(1) = 15.

    depends on sorry what this means

    Statement uses: Eq, Nat, OeisA87719.a, OfNat.ofNat

    Proof uses: Eq.mpr, Nat.find, GT.gt, OeisA87719.countExceeding, OeisA87719.countNotExceeding, OeisA87719.a_exists, id, congrArg, OeisA87719.a.eq_1, And, LT.lt, Not, propext, Nat.find_eq_iff, And.intro, of_decide_eq_true, dite, LE.le, Eq.symm, le_antisymm and 7 more

    27 instances, coercions and auxiliary constants left out.

    Tactic trace: 6 steps

    Open to load the checked before-and-after goal states.

    theorem a_1 : a 1 = 15 := by
    …

    Mentions: OeisA87719.a

  6. theorem OeisA87719.a_2 a(2) = 27 line 66 source

    Source documentation

    a(2) = 27.

    depends on sorry what this means

    Statement uses: Eq, Nat, OeisA87719.a, OfNat.ofNat

    Proof uses: Eq.mpr, Nat.find, GT.gt, OeisA87719.countExceeding, OeisA87719.countNotExceeding, OeisA87719.a_exists, id, congrArg, OeisA87719.a.eq_1, And, LT.lt, Not, propext, Nat.find_eq_iff, And.intro, of_decide_eq_true, dite, LE.le, Eq.symm, le_antisymm and 7 more

    39 instances, coercions and auxiliary constants left out.

    Tactic trace: 6 steps

    Open to load the checked before-and-after goal states.

    theorem a_2 : a 2 = 27 := by
    …

    Mentions: OeisA87719.a

  7. theorem OeisA87719.a_3 a(3) = 57 line 74 source

    Source documentation

    a(3) = 57.

    depends on sorry what this means

    Statement uses: Eq, Nat, OeisA87719.a, OfNat.ofNat

    Proof uses: Eq.mpr, Nat.find, GT.gt, OeisA87719.countExceeding, OeisA87719.countNotExceeding, OeisA87719.a_exists, id, congrArg, OeisA87719.a.eq_1, And, LT.lt, Not, propext, Nat.find_eq_iff, And.intro, of_decide_eq_true, dite, LE.le, Eq.symm, le_antisymm and 7 more

    69 instances, coercions and auxiliary constants left out.

    Tactic trace: 6 steps

    Open to load the checked before-and-after goal states.

    theorem a_3 : a 3 = 57 := by
    …

    Mentions: OeisA87719.a

  8. theorem OeisA87719.a_formula sorry line 84 source

    depends on sorry what this means

    Statement uses: Nat, GE.ge, OfNat.ofNat, Eq, OeisA87719.a, HAdd.hAdd, HPow.hPow, HMul.hMul

    Proof uses: sorryAx, Lean.Name, Bool.false, Lean.Name.num, Lean.Name.str, Lean.Name.anonymous

    20 instances, coercions and auxiliary constants left out.

    Tactic trace: 1 steps

    Open to load the checked before-and-after goal states.