Let \(\mathcal A\) be a central hyperplane arrangement in an \(\ell\)-dimensional vector space over a field of characteristic zero. A pair \((\mathcal A, k)\) consisting of an \(\ell\)-arrangement and a multiplicity \(k: \mathcal A\to {\mathbb N}\) is called an \(\ell\)-multiarrangement as introduced by \textit{G. M. Ziegler} [Singularities, Proc. IMA Participating Inst. Conf., Iowa City/Iowa 1986, Contemp. Math. 90, 345--359 (1989; Zbl 0678.51010)]. The paper under review studies the exponents of \(2\)-multiarrangements because they are important in order to study the freeness of a \(3\)-arrangement. The author composes a basis for \(D(\mathcal A, k)\) in the case where \(\mathcal A\) consists of three lines using \(Q\)-polynomials \(X\choose \lambda\), where \(X\choose \lambda\) is the generalized binomial coefficient of the partition \(\lambda\).