Linkage
The Tutte–Coxeter graph and its construction from the outer automorphisms of \( S_6 \)
Question: how many arXiv papers are updated to their final journal versions? (Answer: about half of them have non-empty journal-reference metadata; G+)
Keleti's conjecture on the ratio of perimeter to area of a union of unit squares (G+)
Reference for mixed graph acyclicity testing? (Still not adequately answered, but the bounty has since expired)
Six-tetrahedron kaleidocycles don't work (but it takes a computer simulation to demonstrate it, because paper ones do; G+)
The new single-divisible-vote last-place-elimination scheme for Hugo nominations (or as they call it, e pluribus Hugo; G+)
Wikipedia blocked in Russia over its refusal to take down information about illegal drugs (since unblocked)
Six points in general position in 3d can be partitioned into triples determining two linked circles
Boulet imagines what physicists in a pixelated world might think of it
Just because a formula looks mathy doesn't mean it makes any sense
Google teaches spammers how to break security to get their ads through
Constructing the Golay error-correcting code from a great dodecahedron (G+)