Merger tree for IMBH seeds growing via three-body dynamics in a cluster with a central escape velocity of 100 km s⁻¹. We show only 100 tracks for each panel for the sake of readability. Stellar BH masses are drawn from the mass distribution in Fig. 5 according to model set S0. Each track corresponds to a different model. We assume that the IMBH seeding and growth starts at redshift z = 2.