A044302 Numbers n such that string 5,6 occurs in the base 9 representation of n but not of n-1.

51, 132, 213, 294, 375, 456, 459, 537, 618, 699, 780, 861, 942, 1023, 1104, 1185, 1188, 1266, 1347, 1428, 1509, 1590, 1671, 1752, 1833, 1914, 1917, 1995, 2076, 2157, 2238, 2319, 2400, 2481, 2562, 2643, 2646, 2724, 2805