The number of Z-convex polyominoes
The Number of [Old-Time] Basketball games with Final Score n:n where the Home Team was never losing but also never ahead by more than w Points
The number of \bar{2}413\bar{5}-avoiding permutations
The Number System of the Permutations Generated by Cyclic Shift
The numbers game and Dynkin diagram classification results
The numbers game, geometric representations of Coxeter groups, and Dynkin diagram classification results
The obstructions for toroidal graphs with no $K_{3,3}$'s
The Occurrence-in-subtuple problem
The octahedron recurrence and gl(n) crystals
The octahedron recurrence and RSK-correspondence
The On-Line Encyclopedia of Integer Sequences
The operator formula for monotone triangles - simplified proof and three generalizations
The Orchard crossing number of an abstract graph
The Orchard Morphism
The Orchard relation of a generic symmetric or antisymmetric function
The Order Dimension of the Poset of Regions in a Hyperplane Arrangement
The order of monochromatic subgraphs with a given minimum degree
The Order of the Giant Component of Random Hypergraphs
The order of the largest complete minor in a random graph
The p-modular Descent Algebra of the Symmetric Group