  Given modular forms $f$ and $g$ of weights $k$ and $\ell$, respectively,
their Rankin-Cohen bracket $[f,g]^{(k, \ell)}_n$ corresponding to a nonnegative
integer $n$ is a modular form of weight $k +\ell +2n$, and it is given as a
linear combination of the products of the form $f^{(r)} g^{(n-r)}$ for $0 \leq
r \leq n$. We use a correspondence between quasimodular forms and sequences of
modular forms to express the Dirichlet series of a product of derivatives of
modular forms as a linear combination of the Dirichlet series of Rankin-Cohen
brackets.
