Numbers n such that $n^2 + \pi(n)$ is prime.

Reference: A228828

noncomputable def OeisA228828.a (n : ℕ) : ℕ

Numbers n such that $n^2 + \pi(n)$ is prime.

Equations

• OeisA228828.a n = Nat.nth (fun (n : ℕ) => Nat.Prime (n ^ 2 + n.primeCounting)) n

theorem OeisA228828.a_zero : a 0 = 2

theorem OeisA228828.a_one : a 1 = 3

theorem OeisA228828.a_two : a 2 = 7

theorem OeisA228828.a.infinite : {x : ℕ | ∃ (n : ℕ), a n = x}.Infinite

Conjecture: the sequence A228828 is infinite.