The series\(\frac{1}{{{2^3}}} - \frac{1}{{{3^3}}}\left( {1 + 2} \right) + \frac{1}{{{4^3}}}\left( {1 + 2 + 3} \right) - \frac{1}{{{5^3}}}\left( {1 + 2 + 3 + 4} \right) + \ldots \infty \) is