Sum of Reciprocals of Powers as Euler Product/Corollary 1/Examples/Zeta(2) over Zeta(4)

Example of Use of Sum of Reciprocals of Powers as Euler Product/Corollary 1

 * $\ds \prod_{\text {$p$ prime} } \paren {1 + p^{-2} } = \dfrac {15 } {\pi^2}$

where the infinite product runs over the prime numbers.