n this paper‎, ‎we investigate suborbital graphs formed by $Nbig(Gamma_0(N)big)$-invariant equivalence relation induced on $hat{mathbb{Q}}$‎. ‎Conditions for being an edge are obtained as a main tool‎, ‎then necessary and ...

‎‎‎The Hosoya index‎, ‎also known as the $Z$ index‎, ‎of a graph is the‎ ‎total number of matchings in it‎. ‎In this paper‎, ‎we study the Hosoya index of the tree structures‎. ‎Our aim is to give some results on $Z$ in ...

Let $G$ be a connected graph with vertex set $V(G)={v_1, v_2,ldots,v_n}$‎. ‎The distance matrix $D=D(G)$ of $G$ is defined so that its $(i,j)$-entry is equal to the distance $d_G(v_i,v_j)$ between the vertices $v_i$ and ...