mathlib3 documentation

number_theory.primorial

Primorial #

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This file defines the primorial function (the product of primes less than or equal to some bound), and proves that primorial n ≤ 4 ^ n.

Notations #

We use the local notation n# for the primorial of n: that is, the product of the primes less than or equal to n.

def primorial (n : ℕ) :

The primorial n# of n is the product of the primes less than or equal to n.

Equations
theorem primorial_pos (n : ℕ) :
theorem primorial_succ {n : ℕ} (hn1 : n ≠ 1) (hn : odd n) :
theorem primorial_add (m n : ℕ) :
primorial (m + n) = primorial m * (finset.filter nat.prime (finset.Ico (m + 1) (m + n + 1))).prod (λ (p : ℕ), p)
theorem primorial_add_dvd {m n : ℕ} (h : n ≤ m) :
primorial (m + n) ∣ primorial m * (m + n).choose m
theorem primorial_add_le {m n : ℕ} (h : n ≤ m) :
primorial (m + n) ≤ primorial m * (m + n).choose m
theorem primorial_le_4_pow (n : ℕ) :