t the intersection of set theory, number theory, and combinatorics is the Calkin-Wilf tree, a beautiful and relatively recent mathematical construction.

This nerdy math shirt features a topological proof of the Fundamental Theorem of Algebra.

At first glance, the shirt on the left looks like a soccer jock shirt – but it’s actually a very nerdy math shirt.
A soccer ball (European football) usually has 12 pentagons and 20 hexagons, arranged in a highly symmetric fashion. The polyhedron most closely resembling this familiar object is the truncated icosahedron, an Archimedean solid.
Archimedean [...]