“…Sticking to one parity sector, say the even one, at the price of not having a unified framework, one finds that the wave functions of the singular oscillator are obtained from those of the harmonic oscillator with an even number of excitations. This is the view taken in [15]. This observation is in keeping with the fact that on the one hand, the states of the harmonic oscillator with a fixed parity support metaplectic representations of su(1, 1) which is then mapped onto the su(1, 1) irreducible representation space spanned by the states of the singular oscillator.…”