There are no iterated morphisms that define the Arshon sequence and the $σ$-sequence

There are only finitely many distance-regular graphs of fixed valency greater than two

There are only finitely many distance-regular graphs with valency k at least three, fixed ratio k2/k and large diameter

There exists no distance-regular graph with intersection array {55,36,11;1,4,45}

There exists no distance-regular graph with intersection array {56,36,9;1,3,48}

There exists no self-dual [24,12,10] code over F5

There is no universal countable random-free graph

Thomassen's Choosability Argument Revisited

Three alternating sign matrix identities in search of bijective proofs

Three Colorability of an Arrangement Graph of Great Circles

Three Counterexamples on Semigraphoids

Three experimental pearls in Costas arrays

Three layer $Q_2$-free families in the Boolean lattice

Three notions of tropical rank for symmetric matrices

Three osculating walkers

Three proofs of the Goulden-Litsyn-Shevelev conjecture on a sequence arising in algebraic geometry

Three Recitations on Holonomic Systems and Hypergeometric Series

Three, four and five-dimensional fullerenes

Three-Colorings of Cubic Graphs and Tensor Operators

Three-dimensional alpha shapes