The Original I Ching
esenfr
← all experiments
序 · the received ordering

The King Wen sequence

The pair rule and the search for a formula

Tap a pair to see whether it is formed by reversal (fan) or by complement (dui).

The Fu Xi sequence is counting in binary from 0 to 63. The King Wen one (the order in which the hexagrams appear in the book) follows no known numerical formula. What it does have is a pair rule: the 64 are grouped two by two, and the second of each pair is the reversal (fan 反) of the first. Only in the 4 pairs whose hexagram is a palindrome (where reversing changes nothing) is the complement (dui 对) used.

32
pairs
28
pairs by reversal (反)
4
pairs by complement (对)
The 32 pairs
1. Qián
111111₂ = 63
complement (dui)
2. Kūn
000000₂ = 0

Hexagram 1 is a palindrome: reversing it leaves it unchanged, so the pair is formed with its line-by-line complement.

Is there a formula? The binary value along the sequence
Fu Xi: the value rises cleanly from 0 to 63 (it is counting)
King Wen: the same value, now with no apparent pattern

Each bar is the binary value of the hexagram at that position. In Fu Xi it is a perfect ramp; in King Wen, noise. Exactly how much noise is measured by the experiment King Wen as a permutation.

The regularity there is: yang lines by position
116324864

Reversal preserves the number of yang lines, and complementation inverts it (yang ↔ 6−yang). That is why within each pair the two bars are equal (reversal) or add up to 6 (complement): the sequence jumps, but never entirely freely.