The Problem
The 64 hexagrams admit two canonical orderings. The binary natural order (commonly called the "Fu Xi sequence," reconstructed by Shao Yong in the 11th century) is the 6-bit counting sequence (000000 → 111111) — mathematically fully ordered. The King Wen sequence is the textual ordering of the received Zhouyi (~1000 BCE) — its organizational logic has been debated for millennia. Han Kangbo called it "not the essence of the Yi"; Zhu Xi deemed it "unknowable."
Historical clarification (Remark 1): The binary natural order was formalized approximately 2,100 years after King Wen. We do not claim or assume that King Wen "rearranged" the binary natural order. Our analysis treats the two orderings as independently defined mathematical objects and characterizes the permutation between them — analogous to comparing two genome sequences without presupposing which is ancestral.
We ask:
What is the cycle structure of the permutation mapping one ordering to the other in S₆₄?
S₆₄ = the symmetric group on 64 elements, containing 64! (≈ 1.27 × 10⁸⁹) possible permutations. The King Wen sequence is one of them.