Apéry's constant
Apéry's constant is a mathematical constant, defined as the infinite sum of the reciprocals of the cubes of the positive integers. In symbols, ζ ( 3 ) = ∑ n = 1 ∞ 1 n 3 {\displaystyle {\begin{aligned}\zeta (3)&=\sum _{n=1}^{\infty }{\frac {1}{n^{3}}}\end{aligned}}} where ζ is the Riemann zeta function.