The rank of connection matrices and the dimension of graph algebras
The rank of edge connection matrices and the dimension of algebras of invariant tensors
The Ratio Monotonicity of the $q$-Derangement Numbers
The Ratio Monotonicity of the Boros-Moll Polynomials
The real loci of the Calogero-Moser spaces and the Shapiro-Shapiro conjecture
The Redheffer matrix of a partially ordered set
The Rees product of posets
The reflexive dimension of a lattice polytope
The Renyi-Ulam pathological liar game with a fixed number of lies
The replacements of signed graphs and Kauffman brackets of links
The representation of the symmetric group on m-Tamari intervals
The Reversal Ratio of a Poset
The Reverse Ultra Log-Concavity of the Boros-Moll Polynomials
The rigidity transition in random graphs
The Ring of Graph Invariants - Graphic Values
The Ring of Malcev-Neumann Series and the Residue Theorem
The ring of multisymmetric functions
The Riordan Group and Symmetric Lattice Paths
The Rogers-Ramanujan Identities, the Finite General Linear Groups, and the Hall-Littlewood Polynomials
The Rogers-Ramanujan-Gordon Theorem for Overpartitions