Linear ramp state in an infinite square well ($\psi (x)=\sqrt{3}x/L^{3/2}$)

The normalized wavefunction $\psi (x)=\sqrt{3}x/L^{3/2}$ on $(0,L)$ has sine coefficients $c_n=(-1{)}^{n+1}\sqrt{6}/(n\pi )$. Its ground-state probability is $6/{\pi }^2$, while its position probability in $(0,L/3)$ is $1/27$. The constant values of $E_n|c_n{|}^2$ make its energy expectation divergent. It is a valid Hilbert space vector but fails the finite-energy Dirichlet boundary-trace condition.