A044151 Numbers n such that string 1,6 occurs in the base 7 representation of n but not of n-1.

13, 62, 91, 111, 160, 209, 258, 307, 356, 405, 434, 454, 503, 552, 601, 637, 699, 748, 777, 797, 846, 895, 944, 993, 1042, 1091, 1120, 1140, 1189, 1238, 1287, 1336, 1385, 1434, 1463, 1483, 1532, 1581, 1630, 1679, 1728, 1777