Erdős Problem 695 #
Reference: erdosproblems.com/695
theorem
erdos_695 :
(∀ {q : ℕ → ℕ},
StrictMono q →
(∀ (i : ℕ), Nat.Prime (q i)) →
(∀ (i : ℕ), q (i + 1) % q i = 1) →
Filter.Tendsto (fun (k : ℕ) => ↑(q k) ^ (1 / ↑k)) Filter.atTop Filter.atTop) ↔ sorry
Let $q_1 < q_2 < \cdots$ be a sequence of primes such that $q_{i + 1} \equiv 1 \pmod{q_i}$. Is it true that $$ \lim_{k \to \infty} q_k^{1/k} = \infty? $$
Is there a sequence of primes $q_1 < q_2 < \cdots$ such that $q_{i + 1} \equiv 1 \pmod{q_i}$ and $$ q(k) \leq \exp(k (\log k)^{1 + o(1)})? $$