Computation of expected values of some connectivity based topological descriptors of random cyclooctane chains

Cyclooctane is a cycloalkane consisting of carbon and hydrogen atoms arranged in a closed ring structure. Cyclooctane chains can be found in various organic compounds and are significant in the field of organic chemistry due to their diverse reactivity and properties. The atom-bond connectivity index ( \(\mathcal{A}\mathcal{B}\mathcal{C}\) $\mathcal{A}\mathcal{B}\mathcal{C}$ ), the geometric-arithmetic index ( \(\mathcal{G}\mathcal{A}\) $\mathcal{G}\mathcal{A}$ ), the arithmetic–geometric index ( \(\mathcal{A}\mathcal{G}\) $\mathcal{A}\mathcal{G}$ ) and the forgotten index ( \(\mathcal{F}\) $\mathcal{F}$ ) are four well-studied molecular descriptors that have found applications in QSPR and QSAR studies. These topological descriptors have shown significant correlations with different physiochemical properties of octane isomers. In this work, the expected values of four degree based topological descriptors for random cyclooctane chains are calculated. An analytical comparison is given between the expected values of \(\mathcal{A}\mathcal{B}\mathcal{C}\) $\mathcal{A}\mathcal{B}\mathcal{C}$ , \(\mathcal{G}\mathcal{A}\) $\mathcal{G}\mathcal{A}$ , \(\mathcal{A}\mathcal{G}\) $\mathcal{A}\mathcal{G}$ , and \(\mathcal{F}\) $\mathcal{F}$ indices of random cyclooctane chains.