Each HPC license is 1 core. For each 'anshpc' task in the license file it enables 1 additional core. Most solvers come with 4 cores enabled by default, so the 'anshpc' tasks start to add from there. 1 task will then enable a total of 5 cores, with the 4 enabled by the solver. You can refer to the Ansys Help on HPC licensing for additional details.