A044186 Numbers n such that string 6,6 occurs in the base 7 representation of n but not of n-1.

48, 97, 146, 195, 244, 293, 336, 391, 440, 489, 538, 587, 636, 679, 734, 783, 832, 881, 930, 979, 1022, 1077, 1126, 1175, 1224, 1273, 1322, 1365, 1420, 1469, 1518, 1567, 1616, 1665, 1708, 1763, 1812, 1861, 1910, 1959, 2008