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Timeline for answer to Sandbox for Proposed Challenges by l4m2

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Feb 5 at 15:06 comment added aeh5040 @l4m2 I am not convinced. I don't know what you mean by "a value promised large enough". Every individual integer is trivially computable. It is sequences that may not be. The sequence mapping n to BB(n) is not because it would require determining which of the n-state TMs halt for each n, which requires solving the halting problem. The (n-1)-state machines are in effect a subset of the n-state ones, but just knowing the max 1s produced by a halting n-state does not help knowing which n-1 state ones halt.
Feb 4 at 15:16 comment added l4m2 @aeh5040 BB(n-1) is uncomputable because we don't have a value promised large enough, but here BB(n) is provided
Feb 3 at 12:04 comment added aeh5040 Isn't this impossible? The BB(n) sequence is not computable. But if there was a program that solved your problem then wouldn't there be a simple modification of it that computed BB(n)?
Jan 30 at 1:37 history edited l4m2 CC BY-SA 4.0
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Jan 9 at 13:38 comment added Wheat Wizard Mod You need to explain your definition of Turing machine a little more. For one I assume you probably mean deterministic Turing machine, but this is worth specifying. Some definitions require that a Turning machine move the tape head on every transition, some definitions allow the tape head to remain fixed. Some definitions require a specific halt state, some halt when there is no transition available. etc. These differences are usually trivial but BB(k) is highly sensitive to them.
Dec 30, 2025 at 5:16 history answered l4m2 CC BY-SA 4.0