(0,0)(1,1)(2,2)(3,3)[2] (0,0)(1,1)(2,2)(3,2)(4,2)[2] (0,0)(1,1)(2,2)(3,2)(4,1)(5,2)(6,2)(7,1)(8,2)(9,2)[2] (0,0)(1,1)(2,2)(3,2)(4,1)(5,2)(6,2)(7,1)(8,2)(9,1)(10,2)(11,1)(12,2)[2] (0,0)(1,1)(2,2)(3,2)(4,1)(5,2)(6,2)(7,1)(8,2)(9,1)(10,2)(11,1)(12,1)(13,1)[2] Length of sequence exceeds 20 at next step.Permalink of this result