A129603 Replace in the binary expansion of n each run of k 0's (or 1's) with 2k-1 0's (or 1's).
0, 1, 2, 7, 8, 5, 14, 31, 32, 17, 10, 23, 56, 29, 62, 127, 128, 65, 34, 71, 40, 21, 46, 95, 224, 113, 58, 119, 248, 125, 254, 511, 512, 257, 130, 263, 136, 69, 142, 287, 160, 81, 42, 87, 184, 93, 190, 383, 896, 449, 226, 455, 232, 117, 238, 479, 992, 497, 250, 503
Offset: 0
Examples
a(1) = 1, as 1 is 1 in binary and single runs stay intact (as 2*1 - 1 = 1). a(9) = 17, as 9 is 1001 in binary and keeping the most and the least significant runs as '1' and changing the center run '00' to '000', we get 10001 in binary, 17 in decimal.