On the extremal total reciprocal edge-eccentricity of trees

On the extremal total irregularity index of n-vertex trees with fixed maximum degree

In the extension of irregularity indices, Abdo et. al. [1] defined the total irregu-larity of a graph G = (V, E) as irrt(G) = 21 Pu,v∈V (G) du − dv, where du denotesthe vertex degree of a vertex u ∈ V (G). In this paper, we investigate the totalirregularity of trees with bounded maximal degree Δ and state integer linear pro-gramming problem which gives standard information about extremal trees a...

On the extremal properties of the average eccentricity

The eccentricity of a vertex is the maximum distance from it to another vertex and the average eccentricity ecc(G) of a graph G is the mean value of eccentricities of all vertices of G. The average eccentricity is deeply connected with a topological descriptor called the eccentric connectivity index, defined as a sum of products of vertex degrees and eccentricities. In this paper we analyze ext...

On super edge-magic total labeling on subdivision of trees

An edge-magic total labeling of a graph G is a one-toone map λ from V (G) ∪ E(G) onto the integers {1, 2, · · · , |V (G) ∪ E(G)|} with the property that, there is an integer constant c such that λ(x) + λ(x, y) + λ(y) = c for any (x, y) ∈ E(G). If λ(V (G)) = {1, 2, · · · , |V (G|} then edge-magic total labeling is called super edgemagic total labeling. In this paper we formulate super edge-magic...

On the edge and total GA indices of some graphs

Total edge irregularity strength of trees

A total edge-irregular k-labelling ξ : V (G) ∪ E(G) → {1, 2, . . . , k} of a graph G is a labelling of vertices and edges of G in such a way that for any different edges e and f their weights wt(e) and wt(f) are distinct. The weight wt(e) of an edge e = xy is the sum of the labels of vertices x and y and the label of the edge e. The minimum k for which a graph G has a total edge-irregular k-lab...