Analysis settles 16 conjectures on cyclic numbers, indicating new insights into Fibonacci averages.
We settle 22 conjectures of Cohen about cyclic numbers (positive integers n with (n,φ(n))=1), proving 16 and disproving 6, and we completely resolve a related OEIS problem about sequences whose running averages are Fibonacci numbers. Highlights include: asymptotics for cyclics between consecutive squares with a second-order term (Conj.~9), Legendre- and k-fold Oppermann-type results in short quadratic intervals (Conj.~6, Conj.~20, and twin cyclics between cubes, Conj.~32), gap and growth analogs (Visser, Rosser, Ishikawa, and a sum-3-versus-sum-2 inequality; Conj.~47,~52,~54,~56), limiting ratios (Vrba and Hassani; Conj.~60,~61), and structure results for Sophie Germain cyclics (Conj.~36,~37). We also resolve two Firoozbakht-type conjectures for cyclics (Conj.~41--42). On the negative side we exhibit counterexamples to the Panaitopol, Dusart, and Carneiro analogs (Conj.~59,~53,~50--51). Finally, for the lexicographically least sequence of pairwise distinct positive integers whose running averages are Fibonacci numbers ({A248982}), we give explicit closed forms for all n and prove Fried's Conjecture~2 asserting the disjointness of the parity-defined value sets (equivalently, Fₙ₊₂+2nFₙ₊₁ is never a Fibonacci number). Proofs in this paper were assisted by GPT-5.
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Duc Le (2025) studied this question.
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