A Munchausen number is a mathematical curiosity: raise each digit to the power of itself, add them all up, and recover the original number. In the seminal paper on this topic, D. Van Berkel derived a bound on such numbers for any given radix, which means that they can be completely enumerated in principle. We present a simpler argument which yields a bound one half the size and show that a radically different approach would be required for further reductions.
"Munchausen Numbers Redux." Missouri J. Math. Sci. 30 (1) 1 - 4, May 2018. https://doi.org/10.35834/mjms/1534384947