It is conjectured that every Tree with edges whose nodes are all trivalent or monovalent can be given a ``magic'' labeling such that the Integers 1, 2, ..., can be assigned to the edges so that the Sum of the three meeting at a node is constant.

**References**

Guy, R. K. ``Unsolved Problems Come of Age.'' *Amer. Math. Monthly* **96**, 903-909, 1989.

© 1996-9

1999-05-26