On the generation and enumeration of some classes of convex polyominoes.
On the genus distribution of -dipoles.
On the Horton-Strahler number for combinatorial tries
On the Horton-Strahler Number for Combinatorial Tries
In this paper we investigate the average Horton-Strahler number of all possible tree-structures of binary tries. For that purpose we consider a generalization of extended binary trees where leaves are distinguished in order to represent the location of keys within a corresponding trie. Assuming a uniform distribution for those trees we prove that the expected Horton-Strahler number of a tree with α internal nodes and β leaves that correspond to a key is asymptotically given by provided that α...
On the non-holonomic character of logarithms, powers, and the th prime function.
On the number of derangements of a sharply k-ply transitive set of permutations.
On the number of descendants and ascendants in random search trees.
On the number of distributive lattices.
On the number of fully packed loop configurations with a fixed associated matching.
On the number of intervals in Tamari lattices. (Sur le nombre d'intervalles dans les treillis de Tamari.)
On the number of labeled -arch graphs.
On the number of matchings in regular graphs.
On the number of non-isomorphic Steiner triples
On the number of permutations admitting an th root.
On the number of possible row and column sums of -matrices.
On the permanents of certain circulant matrices and related Toeplitz matrices. (Über die Permanente gewisser zirkulanter Matrizen und damit zusammenhängender Toeplitz-Matrizen.)
On the powers of Motzkin paths.
On the q-log-Concavity of Gaussian Binomial Coefficients.
On the representation of abstract semigroups by transformation semigroups : Computer investigations.
On the sequence A079500 and its combinatorial interpretations.