Bitfield confusion
 

Hi there,

I'm trying to understand vBulletin's use of bitfields and this has confused me. If anyone can clear it up, I'd appreciate it:

Code:

1
524288
2
4
8
16
32
64
128
256
512
1024
2048
4096
8192
1
16384
32768
65536
131072
262144
1048576
2097152
4194304
8388608

Why does it go:
1, 524288, 2, 4, 8

I thought the generic method to go was: 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, etc?