4 citations · 6 across the 4 of their papers we have counts for
4 papers · 1 filter
Set Partitions and Other Bell Number Enumerated Objects
Fufa Beyene, Jörgen Backelin, Roberto Mantaci +1
In this paper, we study classes of subexcedant functions enumerated by the Bell numbers and present bijections on set partitions. We present a set of permutations whose transpositi…
Edge number report 1: State of the art estimates for
Jörgen Backelin
This first extracted report contains all lower and upper bounds for e-numbers , for , that I know. All but 24 of them are known (exactly).Very little of the pr…
Edge number critical triangle free graphs with low independence numbers
Jörgen Backelin
The structure of all triangle free graphs G = (V,E) with |E| - 6|V| + 13α(G) = 0 is determined, yielding an affirmative answer to a question of Stanisław Radziszowski and Donald Kr…
Binomial posets with non-isomorphic intervals
Jörgen Backelin
The confluent binomial posets with the atomic function A(n) = max (1,2^(n-2)) are classified. In particular, it is shown that in general there are non-isomorphic intervals of the s…