Counting subwords in a partition of a set.
Counting the number of elements in the mutation classes of -quivers.
Counting the number of unavoidable sets of a given size in a finite set of integers.
Counting transitive relations.
Counting upper interactions in Dyck paths.
Counting walks in a quadrant: a unified approach via boundary value problems
The aim of this article is to introduce a unified method to obtain explicit integral representations of the trivariate generating function counting the walks with small steps which are confined to a quarter plane. For many models, this yields for the first time an explicit expression of the counting generating function. Moreover, the nature of the integrand of the integral formulations is shown to be directly dependent on the finiteness of a naturally attached group of birational transformations...
Counting with groups and rings.
Counting words by number of occurrences of some patterns.
Coupon collecting with quotas.
Covering Sets by Subsets.
Cranks and t-cores.
Crossings and nestings in tangled diagrams.
Cycle index, weight enumerator, and Tutte polynomial.
Cycle lengths in a permutation are typically Poisson.
Cycle peaks and partial derivatives. (Pics de cycles et dérivés partielles.)
Cyclic derangements.
Cyclic permutations of sequences and uniform partitions.
Cyclic sieving phenomenon in non-crossing connected graphs.