This function can be defined recursively as n times this function for n minus one.
Brocard's problem asks which outputs of this function are one less than a perfect square, and Christian Kramp was the first to use the notation commonly used to denote this function. By Stirling's approximation, the natural log of this function on n is equal to n natural log of n all minus n. It is extended to all the complex numbers except the non-positive integers by the gamma function, and the Taylor series of e to the x features this function acting in the denominator of the polynomial terms. This function can be defined recursively as n times this function for n minus one. For 10 points, name this function denoted by an exclamation mark.
Brocard's problem asks which outputs of this function are one less than a perfect square, and Christian Kramp was the first to use the notation commonly used to denote this function.
factorial