New posts in Combinatorics

Count all binary relations

The Caged Circles

Centerless Polygons

The square root of the square root of the square root of the…

Rectangles in rectangles

Sequences of distinct positive integers

Extend the most recent "nice" OEIS sequence: stepping stone puzzle on a grid

Cut a triangle into equal-sized parts!

Triangles in a tetrahedron

Spanning paths in a tournament on n nodes