References: Inder J. Taneja, Crazy Representations of Natural Numbers – The 10958 Problem,  https://inderjtaneja.com/2018/11/16/crazy-representations-of-natural-numbers-the-10958-problem/Inder J. Taneja, Factorial-Power Selfie Expressions, Zenodo, February 20, 2019, pp. 1-115,  http://doi.org/10.5281/zenodo.2573569Inder J. Taneja, Single Digits Representations, https://inderjtaneja.com/2019/01/01/single-letter-representations-of-numbers-from-1-to-20000/