Getzler-Kapranov graph complex cohomology computations in weight 13

We study the weight-graded compactly supported cohomology of the moduli spaces of curves ${\mathcal{M}}_{g,n}$ using the Getzler-Kapranov graph complex. After recollecting the theory and some previous results, we compute the cohomology in weight 13 for the (g, n) pairs with 3g + 2n = 28.