The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A337025 Number of n-state 2-symbol halt-free Turing machines. 0
 1, 16, 4096, 2985984, 4294967296, 10240000000000, 36520347436056576, 182059119829942534144, 1208925819614629174706176, 10314424798490535546171949056, 109951162777600000000000000000000, 1432052311740255546466984939315265536 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS A Turing machine is halt-free if none of its instructions lead to the halt state. This sequence is strictly less than A052200(n) for all n > 0, since halt-free n-state machines are a strict subset of all n-state machines. Solutions to the so-called "Beeping Busy Beaver" problem will almost certainly be halt-free programs. LINKS Scott Aaronson, The Busy Beaver Frontier. Nick Drozd, Beeping Busy Beavers. FORMULA a(n) = ((4*n)^2)^n. PROG (Python) [((4 * n) ** 2) ** n for n in range(12)] CROSSREFS Cf. A052200. Sequence in context: A016936 A321242 A013721 * A053859 A053863 A053765 Adjacent sequences:  A337022 A337023 A337024 * A337026 A337027 A337028 KEYWORD nonn,easy AUTHOR Nicholas Drozd, Aug 11 2020 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified May 16 19:46 EDT 2021. Contains 343951 sequences. (Running on oeis4.)