n ≥ 3 boxes are placed around a circle. At the first step we choose some boxes. At the second step for each chosen box we put a ball into the chosen box and into each of the two neighboring boxes. Find the total number of possible distinct ball distributions which can be obtained in this way. (All balls are identical.)
Correct Solutions by,
- Toshihiro Shimizu Kawasaki, Japan
- Steffen Weber Ismaning, Germany
- Solution: http://www.fen.bilkent.edu.tr/~cvmath/Problem/1805a.pdf