“…Such indices include the subtree number (also called ρ-index in [13]), number of leaf-containing subtrees (also called "acceptable residue configurations" [14]), BC-subtree number [15], general vertex-degree-based indices [16][17][18], atom-bond connectivity [19][20][21][22], Merrifield-Simmons index (number of independent vertex subsets [13]), the Hosoya index (number of matchings [23,24]), the Kirchhoff index [25][26][27], the Zagreb index [28][29][30][31][32], the Randić index [33][34][35][36], the Szeged index [11,37,38], and the PI index [39,40]. As one of the main structure-based and counting-based indices, the number of subtrees is known to be "negatively correlated" with the Wiener index [41].…”