A031490 Numbers n which in base 8 has one fewer 0's than 7's.

7, 15, 23, 31, 39, 47, 55, 57, 58, 59, 60, 61, 62, 79, 87, 95, 103, 111, 119, 121, 122, 123, 124, 125, 126, 143, 151, 159, 167, 175, 183, 185, 186, 187, 188, 189, 190, 207, 215, 223, 231, 239, 247, 249, 250, 251, 252, 253, 254, 271