A044155 Numbers n such that string 2,3 occurs in the base 7 representation of n but not of n-1.

17, 66, 115, 119, 164, 213, 262, 311, 360, 409, 458, 462, 507, 556, 605, 654, 703, 752, 801, 805, 833, 899, 948, 997, 1046, 1095, 1144, 1148, 1193, 1242, 1291, 1340, 1389, 1438, 1487, 1491, 1536, 1585, 1634, 1683, 1732, 1781