A094511 Smallest number distinct from n, not occurring earlier and having in binary representation not more ones than n.

2, 1, 4, 8, 3, 5, 6, 16, 10, 9, 7, 17, 11, 12, 13, 32, 18, 20, 14, 24, 19, 21, 15, 33, 22, 25, 23, 26, 27, 28, 29, 64, 34, 36, 37, 40, 35, 41, 30, 48, 38, 44, 39, 42, 43, 45, 31, 65, 50, 49, 46, 56, 51, 52, 47, 66, 53, 54, 55, 57, 58, 59, 60, 128, 68, 72, 69, 80, 67, 73, 70