%N Largest possible difference between consecutive marks that can occur amongst all possible perfect rulers of length n.
%C For nomenclature related to perfect and optimal rulers see Peter Luschny's "Perfect Rulers" web pages.
%H Peter Luschny, <a href="http://www.luschny.de/math/rulers/introe.html">Perfect and Optimal Rulers.</a> A short introduction.
%H Hugo Pfoertner, <a href="http://www.randomwalk.de/scimath/diffset/consdifs.txt">Largest and smallest maximum differences of consecutive marks of perfect rulers.</a>
%H <a href="/index/Per#perul">Index entries for sequences related to perfect rulers.</a>
%e There are 6 perfect rulers of length 13: [0,1,2,6,10,13], [0,1,4,5,11,13], [0,1,6,9,11,13] and their mirror images. The maximum difference between adjacent marks occurs for the second ruler between marks "5" and "11". Therefore a(13)=6.
%Y Cf. A104306 corresponding occurrence counts.
%A _Hugo Pfoertner_, Feb 28 2005