G4G8 Exchange Book
The black nodes mark the corners of an octagon and each of these nodes in connected to four others by lines. The (rather hard) puzzle is to assign the sixteen numbers 0 through 15 to each of the sixteen lines so that each black node has a sum of 30 when the line numbers leading into it are added.
The word version of the puzzle was described in the article "Most-Perfect Word Magic", Oscar Thumpbindle, Word Ways Vol. 40(4). Nov. 2007.
This is an electronic copy of a paper originally appearing in the G4G8 Exchange Book. Archived with permission. The author(s) reserves all rights.
Farrell, Jeremiah and Rodgers, Tom, "The Magic Octagon" G4G8 Exchange Book / (2008): 135-137.
Available at http://digitalcommons.butler.edu/facsch_papers/918