1. A. M. J. High School, Mankhamar, Bankura-722144, West Bengal, India
2. Department of Mathematics and Statistics, College of Science, Imam Mohammad Ibn Saud Islamic University (IMSIU), P.O. Box-65892, Riyadh 11566, Saudi Arabia
3. Department of Mathematics, The University of Burdwan, Golapbag, Burdwan-713104, West Bengal, India