Spanning trees and function classes.
Spectral properties of a certain class of Carleman operators
The object of the present work is to construct all the generalized spectral functions of a certain class of Carleman operators in the Hilbert space and establish the corresponding expansion theorems, when the deficiency indices are (1,1). This is done by constructing the generalized resolvents of and then using the Stieltjes inversion formula.
Square-ice enumeration.
Staircases in .
Standard paths in another composition poset.
Statistics on Dyck paths.
Stirling pairs
Strings with maximally many distinct subsequences and substrings.
Struktur- und Anzahlformeln für Topologien auf endlichen Mengen.
Subsequence containment by involutions.
Succession rules and deco polyominoes
Succession rules and Deco polyominoes
In this paper, we examine the class of "deco" polyominoes and the succession rule describing their construction. These polyominoes are enumerated according to their directed height by factorial numbers. By changing some aspects of the "factorial" rule, we obtain some succession rules that describe various "deco" polyomino subclasses. By enumerating the subclasses according to their height and width, we find the following well-known numbers: Stirling numbers of the first and second kind,...
Sums of Powered Characteristic Roots Count Distance-Independent Circular Sets
Significant values of a combinatorial count need not fit the recurrence for the count. Consequently, initial values of the count can much outnumber those for the recurrence. So is the case of the count, Gl(n), of distance-l independent sets on the cycle Cn, studied by Comtet for l ≥ 0 and n ≥ 1 [sic]. We prove that values of Gl(n) are nth power sums of the characteristic roots of the corresponding recurrence unless 2 ≤ n ≤ l. Lucas numbers L(n) are thus generalized since L(n) is the count in question...
Sums of reciprocals of the central binomial coefficients.
Sur la formule d’inversion de Lagrange
On se propose de démontrer que la formule d’inversion de Lagrange est encore valide sur un anneau commutatif, même pour une série ayant quelques termes à coefficients nilpotents avant le terme de degré 1 (dont le coefficient est inversible). On n’use que de techniques algébriques.
Sur les permutations circulaires distinctes
Symbol-crunching with the transfer-matrix method in order to count skinny physical creatures.
Symbolic summation assists combinatorics.
Symmetric inclusion-exclusion.
Symmetric monoidal completions and the exponential principle among labeled combinatorial structures.