hey. I've had no education in factorials specifically, but my professor is expecting us to already know this stuff... In a problem where factorials are included, it is claimed (2n+2)! = (2n+2)*(2n+1)*(2n)!. Shouldn't it be (2n+2)!= (2n+2)*2n! ? In addition, is there any difference between 2n! and (2n)! ?