prob023: magic hexagon

proposed by Toby Walsh
tw@cs.york.ac.uk

References

The magic hexagon was found in 1895 after much trial and error by William Radcliffe.

In 1963, Charles Trigg proved that it is the only magic hexagon of any size (other than the trivial diameter 1) using a constraint on the sum of any diagonal.

See the related magic square and sequence problem entry.