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A337025
Number of n-state 2-symbol halt-free Turing machines.
0
1, 16, 4096, 2985984, 4294967296, 10240000000000, 36520347436056576, 182059119829942534144, 1208925819614629174706176, 10314424798490535546171949056, 109951162777600000000000000000000, 1432052311740255546466984939315265536
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.
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
KEYWORD
nonn,easy
AUTHOR
Nicholas Drozd, Aug 11 2020
STATUS
approved