Question 3
A collection of $n$ squares on the plane is called tri-connected if:
(i) all squares are congruent;
(ii) if two squares have a point $P$ in common, then $P$ is a vertex of each square;
(iii) each square touches exactly three other squares.
How many positive integers $n$ with $2018\le n\le3018$ admit such a collection?
(i) all squares are congruent;
(ii) if two squares have a point $P$ in common, then $P$ is a vertex of each square;
(iii) each square touches exactly three other squares.
How many positive integers $n$ with $2018\le n\le3018$ admit such a collection?