A043448 Numbers n such that number of 6's in base 8 is 4.

3510, 7606, 11702, 15798, 19894, 23990, 25014, 25526, 26038, 26550, 27062, 27574, 27702, 27766, 27830, 27894, 27958, 28022, 28038, 28046, 28054, 28062, 28070, 28078, 28080, 28081, 28082, 28083, 28084, 28085, 28087