MathDB

Choose a four-digit number (none of them zero) and, starting with it, build a list of

21

different numbers, each with four digits, that satisfies the following rule: after writing each new number in the list, all the averages are calculated Between two digits of that number, those averages that do not give a whole number are discarded, and with the rest a four-digit number is formed that will occupy the next place in the list. For example, if

2946

was written in the list, the next one can be

3333

3434

5345

or any other number armed with the figures

3

4

5

Problem Statement