A393210 - OEIS

%I #10 Feb 07 2026 15:59:38

%S 1,5,1,13,1,5,1,29,1,5,1,13,1,5,1,61,1,5,1,13,1,5,1,29,1,5,1,13,1,5,1,

%T 125,1,5,1,13,1,5,1,29,1,5,1,13,1,5,1,61,1,5,1,13,1,5,1,29,1,5,1,13,1,

%U 5,1,253,1,5,1,13,1,5,1,29,1,5,1,13,1,5,1,61

%N Halting time for Wolfram's 2-state 2-symbol Turing machine 3626 when started with n on the tape.

%C Machine 3626 computes the identity function. This machine exhibits exponential growth in halting time and should be compared with machine 3589 (linear time) and machine 3197 (constant time) which both also compute the identity function.

%H Sean A. Irvine, <a href="/A393210/b393210.txt">Table of n, a(n) for n = 1..1000</a>

%H Stephen Wolfram, <a href="https://writings.stephenwolfram.com/2026/01/p-vs-np-and-the-difficulty-of-computation-a-ruliological-approach/">P vs. NP and the Difficulty of Computation: A Ruliological Approach</a>, 2026.

%t With[{lim = 120}, PacletSymbol["WolframInstitute/TuringMachine", "OneSidedTuringMachineFunction"][{3626, 2, 2}, {1, lim}, lim, "Steps"] ] (* _Michael De Vlieger_, Feb 07 2026, after 5th example in "The Basic Setup" in the Wolfram article *)

%Y Cf. A392245, A010684 (halting time for machine 3197), A037227 (halting time for machine 3589).

%K nonn

%O 1,2

%A _Sean A. Irvine_, Feb 05 2026