$(GDR 4)$ Find the maximal number of regions into which a sphere can be partitioned by $n$ circles.
Problem
Source:
Tags: geometry, 3D geometry, sphere, dissection, combinatorics, IMO Shortlist, IMO Longlist
Source:
Tags: geometry, 3D geometry, sphere, dissection, combinatorics, IMO Shortlist, IMO Longlist
$(GDR 4)$ Find the maximal number of regions into which a sphere can be partitioned by $n$ circles.