Does that equation have a name? A naive google search doesn't return anything. Edit: Found it. A is known as Mill's constant https://en.wikipedia.org/wiki/Mil

Does that equation have a name? A naive google search doesn't return anything. Edit: Found it. A is known as Mill's constant https://en.wikipedia.org/wiki/Mills%27_constant https://en.wikipedia.org/wiki/Mills%27_constant