A fullerene is a molecule composed of carbon in the shape of a hollow sphere, ellipsoid, tube, and many other forms. The spherical ones are called buckyballs and they look like the balls used in football game. The first ...

The Hosoya polynomial of a molecular graph G is defined as H(G,x)=∑u,vϵV(G)xd(u,v),  where the sum is over all unordered pairs {u,v} of distinct vertices in G. In this paper we arrange the main result ...

The geometric-arithmetic index is a topological index was defined as $GA(G)=sum{uvin E(G)}frac{2sqrt{d_ud_v}}{d_u+d_v}}$, where du denotes the degree of vertex u in G. By replacing instead $delta_u=sum_{vcong ...

The eccentric connectivity index of a graph is defined as E(Γ)=∑uεV(Γ)degΓ(u)e(u), where degΓ(u) denotes the degree of the vertex u in Γ and e(u) is the eccentricity of vertex u. In this ...