Erdős problem 516
Let f = ∑ aₖzⁿₖ be an entire function of finite order such that nₖ / k → ∞. Then limsup (fun r => ratio r f) atTop = 1. This is proved in [Fu63].
Sources
FormalConjectures/ErdosProblems/
516.lean
Retained formal statement
Let f = ∑ aₖzⁿₖ be an entire function such that nₖ > k (log k) ^ (2 + c). Then limsup (fun r => ratio r f) atTop = 1. This is proved in [Ko65].
∀ {f : ℂ → ℂ} {n : ℕ → ℕ}, (∃ c > 0, ∀ (k : ℕ), ↑(n k) > ↑k * Real.log ↑k ^ (2 + c)) → ∀ {a : ℕ → ℂ}, (∀ (n : ℕ), a n ≠ 0) → (∀ (z : ℂ), HasSum (fun k => a k * z ^ n k) (f z)) → Filter.limsup (fun r => Erdos516.ratio r f) Filter.atTop = 1SolvedStatement only, no proof