A044133 Numbers n such that string 5,1 occurs in the base 6 representation of n but not of n-1.

31, 67, 103, 139, 175, 186, 211, 247, 283, 319, 355, 391, 402, 427, 463, 499, 535, 571, 607, 618, 643, 679, 715, 751, 787, 823, 834, 859, 895, 931, 967, 1003, 1039, 1050, 1075, 1111, 1116, 1183, 1219, 1255, 1266, 1291, 1327