How to calculate $\left|\langle\psi,(1j)\rangle\right| $ where $ \psi=(12 \cdots n).$
I am considering which $j$ makes $\langle\psi,(1j)\rangle=S_{n}.$One of my friends told me that I can even calculate $\left|\langle\psi,(1j)\rangle\right|$.But I have no idea where to start.Any help will be thanked.