Heath-Brown–Moroz constant

The Heath-Brown–Moroz constant C, named for Roger Heath-Brown and Boris Moroz, is defined as C = ∏ p ( 1 − 1 p ) 7 ( 1 + 7 p + 1 p 2 ) = 0.001317641... {\displaystyle C=\prod _{p}\left(1-{\frac {1}{p}}\right)^{7}\left(1+{\frac {7p+1}{p^{2}}}\right)=0.001317641...} where p runs over the primes.

Source: Wikipedia — Heath-Brown–Moroz constant (CC BY-SA 4.0)