The sequence composed of 1s and 2s obtained by starting with the number 1, and picking subsequent elements to avoid repeating the longest possible substring. The first few terms are 1, 2, 1, 1, 2, 2, 1, 2, 1, 1, 2, 1, 2, 2, … (Sloane’s A006345). The Sally sequence gives the length of the run that was avoided. (From Wolfram’s Mathworld)
