A044250 Numbers n such that string 7,7 occurs in the base 8 representation of n but not of n-1.

63, 127, 191, 255, 319, 383, 447, 504, 575, 639, 703, 767, 831, 895, 959, 1016, 1087, 1151, 1215, 1279, 1343, 1407, 1471, 1528, 1599, 1663, 1727, 1791, 1855, 1919, 1983, 2040, 2111, 2175, 2239, 2303, 2367, 2431, 2495, 2552