References
- H.G. Grundman and E.A. Teeple, Iterated Sums of Fifth Powers of Digits, Rocky Mountain J. Math. 38(2008), no.4, 1139-1146. https://doi.org/10.1216/RMJ-2008-38-4-1139
- N.P. Singh, On the Sum of Powers of Digits of a Number, Parabola, 41(2005), no.1, 1-2.