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Terras’ Coefficient Stopping Time (CST) conjecture

Prove that for every integer n ≥ 2, the stopping time t(n) (the least j with T^j(n) < n) equals the coefficient stopping time τ(n) (the least j with C_j(n) = 3^{q_j(n)}/2^j < 1) for the Collatz map T.

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Background

The authors define the stopping time t(n) as the least j with Tj(n) < n and the coefficient stopping time τ(n) as the least j with C_j(n) = 3{q}/2{j} < 1. It is immediate that t(n) ≥ τ(n).

Terras conjectured equality for all n ≥ 2. This CST conjecture is significant because it would imply the nonexistence of nontrivial cycles. The paper’s paper of paradoxical sequences provides computational support to CST up to very large bounds.

References

Terras' Coefficient Stopping Time (CST) conjecture asserts that equality holds for all $n \geq 2$.

Paradoxical behavior in Collatz sequences (2502.00948 - Rozier et al., 2 Feb 2025) in Section 1 (Introduction), after Definition 1.1 (Stopping time and coefficient stopping time)