DescriptionRecent developments in the study of chromatin loop domains and gene regulation motivates us to investigate the topology of contacts in interacting polymers. To describe the chromatin loop formation we will use a bead on a string model with excluded volume and attractive polymer-polymer interaction simulated by self avoiding walks. The resulting chain configuration is a balance between these two interactions and can be a coiled state for good solvents or a collapsed one for poor solvent. We can classify the different chain configurations by their topological structures through the genus, a topological invariant of the resulting diagrams. The backtracking algorithm enables us to achieve exact numerical results for the genus distribution of the above mentioned model for small polymer lengths. Since pseudoknots decrease the entropy by restricting the possible configuration, we explore whether we see a suppression of pseudoknots for finite size polymers and intermediate strength of interaction.