In 1998, Bird introduced Meertens numbers as numbers that are invariant under a map similar to the Gödel encoding. In base 10, the only known Meertens number is 81312000. We look at some properties of Meertens numbers and consider variations of this concept. In particular, we consider variations of Meertens numbers where there is a finite time algorithm to decide whether such numbers exist, exhibit infinite families of these variations and provide bounds on parameters needed for their existence.
Wu, Chai Wah
"Meertens number and its variations,"
Communications on Number Theory and Combinatorial Theory: Vol. 3, Article 5.
Available at: https://research.library.kutztown.edu/contact/vol3/iss1/5