Three test tubes contain numbered balls. The first tube can contain three balls, the middle tube two, and the last tube only one. They start out in the configuration shown at left, and your task is to move one ball at a time from one tube to another without exceeding the tube's capacity, until the numbered balls are in the configuration on the right.

What's the minimum number of moves of individual balls and what's the sequence of moves?

 | |                      | |
 |3|   | |        ====>   |3|   | |
 |1|   |2|   | |          |2|   | |   |1|
  =     =     =            =     =     =

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From Daily Brain Games calendar 2020, by HAPPYneuron, Andrews McMeel Publishing, Kansas City, MO. Puzzle for July 10.