proposed by | Peter van Beek vanbeek@cs.ualberta.ca |
Note that a symmetry can be removed by adding the constraint that a_2 - a_1 < a_m - a_{m-1}, the first difference is less than the last.
There exist several interesting generalizations of the problem which have received attention like modular Golomb rulers (differences are all distinct mod a given base), disjoint Golomb rulers, Golomb rectangles (the 2-dimensional generalization of Golomb rulers), and difference triangle sets (sets of rulers with no common difference).