A043415 Numbers n such that number of 5's in base 7 is 3.

285, 628, 971, 1314, 1657, 1755, 1804, 1853, 1902, 1951, 1965, 1972, 1979, 1986, 1993, 1995, 1996, 1997, 1998, 1999, 2001, 2007, 2049, 2343, 2686, 3029, 3372, 3715, 4058, 4156, 4205, 4254, 4303, 4352, 4366, 4373, 4380