How to prove that the number $1!+2!+3!+...+n! \ \forall n \geq 4$ is never square?
I was told to count permutations but I cannot figure out what we are permuting.... Thanks!
How to prove that the number $1!+2!+3!+...+n! \ \forall n \geq 4$ is never square?
I was told to count permutations but I cannot figure out what we are permuting.... Thanks!