You have a (solid) blue cube and an unlimited amount of (solid) red cubes, all of which are of the same size. What is the largest number of red cubes that can touch the blue cube along its sides or parts of its sides?
Touching along edges or at corner points do not count.
Problem comes from Pi Han Goh (https://brilliant.org/problems/he-was-wrong-too/?group=3BX9rjPrQ3CM&ref_id=820890)
Comment what you think is the answer, with some graphics if possible.
My 21 configuration that worked
Michael Mendrin’s 22 configuration.