规定x@y=x*(x+1)*(x+2)*…*(x+y-1),如2@4=2*3*4*5.已知n+1/n@3=1/575,求自然数n

题目

规定x@y=x*(x+1)*(x+2)*…*(x+y-1),如2@4=2*3*4*5.已知n+1/n@3=1/575,求自然数n
做得好我会额外加分的!

答案

n@3=n(n+1)(n+2)
n+1/n@3=1/575
1/n(n+2)=1/575
n^2+2n-575=0
n=23