J. Appl. Math. Comput. DOI 10.1007/s12190-016-1027-6 ORIGINAL RESEARCH Computing topological indices of Sudoku graphs Wei Gao 1 · Muhammad Imran 2 · Abdul Qudair Baig 3 · Haidar Ali 3 · Mohammad Reza Farahani 4 Received: 6 April 2016 © Korean Society for Computational and Applied Mathematics 2016 Abstract In QSAR/QSPR study, physico-chemical properties and topological indices such as Randi´ c, atom-bond connectivity ( ABC ) and geometric-arithmetic (GA) index are used to predict the bioactivity of chemical compounds. A topological index is actually designed by transforming a chemical structure into a numeric number. These topological indices correlate certain physico-chemical properties like boiling point, stability, strain energy etc. of chemical compounds. Graph theory has found a consid- erable use in this area of research. The topological indices of certain interconnection networks were studied recently by Imran et al. (Appl Math Comput 244:936–951, 2014). In this paper, we extend this study to n × n Sudoku graphs and derive analytical B Mohammad Reza Farahani mrfarahani88@gmail.com Wei Gao gaowei@ynnu.edu.cn Muhammad Imran imrandhab@gmail.com Abdul Qudair Baig aqbaig1@gmail.com Haidar Ali haidar3830@gmail.com 1 School of Information Science and Technology, Yunnan Normal University, Kunming 650500, China 2 Department of Mathematics, School of Natural Sciences (SNS), National University of Sciences and Technology (NUST), Sector H-12, Islamabad, Pakistan 3 Department of Mathematics, COMSATS Institute of Information Technology, Attock, Pakistan 4 Department of Applied Mathematics, Iran University of Science and Technology (IUST), 16844 Tehran, Narmak, Iran 123