Range measured: level 0, 16047040..16737344, sampled as the first 65536
bytes. Cross-checked on every level that has the region, each sampled the
same way from its own region start.
Method: autocorrelation. For each candidate stride, count how often a 4-byte
sequence at offset i repeats at i + stride, as a fraction of comparable
positions. A random control of the same size measured identically reads flat
at 0.0000 for every stride, so the statistic does discriminate.
stride 368 0.1110
stride 340 0.0935
strides 337-339 0.026-0.029 background
random control 0.0000
Stride 368 is the strongest peak. On level 0, 340 is a secondary peak well
clear of the background; the two differ by 28, unexplained.
The cross-check is the part that matters: the peak stride was recomputed
independently for every level with the region, and all 24 peak at exactly
368. One level's peak could be a property of that level's data; 24 of 24
agreeing is a format invariant.
What a 368-byte record is remains unestablished. This is the same position
the shrub body was in before differential analysis identified its records,
and the same method is the obvious next step -- apply it to the 368 stride
rather than continuing to look for headers.
Chosen deliberately over the header search: autocorrelation found this in one
pass with a control, where four header guesses found nothing. The shrub body
only yielded to differential analysis too, and pattern-matching is what
produced this session's four retractions.
ReaperOfVeriod
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