  Following the simple proposal by He and Ma for quantization of a black
hole(BH) by Bohr's idea about the atoms, we discussed the solvability of the
wave equation for such a BH. We superficial solved the associated Schrodinger
equation. The eigenfunction problem reduces to HeunB $H$ differential equation
which is a natural generalization of the hypergeometric differential equation.
In other words, the spectrum can be determined by solving the Heun's
differential equation.
