golomb_ruler (759B)
1 # Golomb ruler 2 3 https://en.wikipedia.org/wiki/Golomb_ruler 4 5 set of [natural_numbers] such that no difference (in [absolute_value]) is achieved twice 6 7 - order: number of elements of the set 8 - length: value of the greatest integer 9 - optimal ruler: no ruler of the same order and of smaller length exists (optimally short) 10 - also optimally dense: no rules exists with greater order and same length 11 - perfect ruler https://en.wikipedia.org/wiki/Perfect_ruler : every distance below a certain bound is achieved exactly once 12 - optimal perfect ruler: minimal length (largest value) 13 - no perfect golomb ruler for five or more marks exists 14 - cf http://cgm.cs.mcgill.ca/~athens/cs507/Projects/2003/JustinColannino/ 15 16 Up: [combinatorics] 17 18 See also: [sidon_set]