I have read that for the Landau function $g(n)$ (http://mathworld.wolfram.com/LandausFunction.html), one knows that $\lim_{n \rightarrow \infty} g(n+1)/g(n) = 1$ I wonder whether someone has derived an explicit constant bound in the sense that $g(n+1) \leq C g(n)$ for $n \geq N$ where $C$ and $N$ can be given explicitly (and $N$ is "small").