ID NAME QUALITY USERS ACC % DIFFICULTY C I
23963 Easy Factorials   11 86
27
26

#factorial

factorial of a non-negative integer n, denoted by n!, is the product of all positive integers less than or equal to n

https://en.wikipedia.org/wiki/Factorial http://mathworld.wolfram.com/Factorial.html http://www.programmingsimplified.com/c-program-find-factorial