The number of 1-factors in some polyhexes.
The Number Of Antichains Of Finite Power Sets
The number of antichains of finite power sets.
The number of binomial coefficients in residue classes modulo p and .
The number of certain -combinations of an -set.
The number of complete exceptional sequences for a Dynkin algebra
The Dynkin algebras are the hereditary artin algebras of finite representation type. The paper determines the number of complete exceptional sequences for any Dynkin algebra. Since the complete exceptional sequences for a Dynkin algebra of Dynkin type Δ correspond bijectively to the maximal chains in the lattice of non-crossing partitions of type Δ, the calculations presented here may also be considered as a categorification of the corresponding result for non-crossing partitions.
The number of crossings in a regular drawing of the complete bipartite graph.
The number of elements in the mutation class of a quiver of type .
The number of -matchings in almost every tree is a zero residue.
The number of graphs not containing as a minor.
The number of indecomposable Schur rings over a cyclic 2-group.
The number of inequivalent optimal covering codes.
The number of inversions in permutations: A saddle point approach.
The number of knight's tours equals 33, 439, 123, 484, 294—counting with binary decision diagrams.
The number of labeled 2-connected planar graphs.
The number of [old-time] basketball games with final score : where the home team was never losing but also never ahead by more than points.
The number of orthogonal Latin squares
The number of prime factors of binomial coefficients
The number of ternary words avoiding abelian cubes grows exponentially.
The number of triangles formed by intersecting diagonals of a regular polygon.