The conjecture $A159634(n) = \psi(2n)/3$ where $\psi$ is the Dedekind psi function.

Steven Finch is the author of the OEIS-sequence A159634 which is defined as

"Coefficient for dimensions of spaces of modular & cusp forms of weight $k/2$, level $4n$ >and trivial character, where $k \ge 5$ is odd."

Recently Enrique Pérez Herrero conjectured that this sequence is given by $\psi(2n)/3$ where $\psi(n)$ is the Dedekind psi function:

$$A159634(n) = \psi(2n)/3$$

Finch refers to a paper of H. Cohen and J. Oesterle, "Dimensions des espaces de formes modulaires, Modular Functions of One Variable." Can someone shed some light on this conjecture or prove / disprove it?