De Bruijn-like sequence for `2^n - 1`: how is it constructed?

Question

I\'m looking at the entry Find the log base 2 of an N-bit integer in O(lg(N)) operations with multiply and lookup from Bit Twiddling hacks.

I can easily see how t

Answer 1

From: http://www.stmintz.com/ccc/index.php?id=306404

130329821
0x07C4ACDD
00000111110001001010110011011101B

bit 31 - bit 27   00000  0
bit 30 - bit 26   00001  1
bit 29 - bit 25   00011  3
bit 28 - bit 24   00111  7
bit 27 - bit 23   01111 15
bit 26 - bit 22   11111 31
bit 25 - bit 21   11110 30
bit 24 - bit 20   11100 28
bit 23 - bit 19   11000 24
bit 22 - bit 18   10001 17
bit 21 - bit 17   00010  2
bit 20 - bit 16   00100  4
bit 19 - bit 15   01001  9
bit 18 - bit 14   10010 18
bit 17 - bit 13   00101  5
bit 16 - bit 12   01010 10
bit 15 - bit 11   10101 21
bit 14 - bit 10   01011 11
bit 13 - bit  9   10110 22
bit 12 - bit  8   01100 12
bit 11 - bit  7   11001 25
bit 10 - bit  6   10011 19
bit  9 - bit  5   00110  6
bit  8 - bit  4   01101 13
bit  7 - bit  3   11011 27
bit  6 - bit  2   10111 23
bit  5 - bit  1   01110 14
bit  4 - bit  0   11101 29
bit  3 - bit 31   11010 26 
bit  2 - bit 30   10100 20
bit  1 - bit 29   01000  8
bit  0 - bit 28   10000 16

It seems to me that 0x07C4ACDD is a 5-bit de Bruijn sequence.