

A081419


Largest value held in any register at the end of a halting computation by an ninstruction register Minski machine.


1




OFFSET

1,3


COMMENTS

We start with initially empty registers and include exactly one Halt instruction. Analogous to the Busy Beaver function, Sigma, for Turing Machines.
n<=5 are proved. 5<n<=9 are good lower bounds.


REFERENCES

Tibor Rado, On Noncomputable Functions, Bell System Technical Journal, vol. 41, # 3, 877884, May 1963.


LINKS

Table of n, a(n) for n=1..9.


FORMULA

Noncomputable.


EXAMPLE

E.g. B(3) is of the form:
1: A+ > 2
2: A+ > 3
3: Halt
Halting with B(3)=2


CROSSREFS

Cf. A028444.
Sequence in context: A215285 A275173 A295394 * A108858 A294688 A094859
Adjacent sequences: A081416 A081417 A081418 * A081420 A081421 A081422


KEYWORD

hard,nice,nonn


AUTHOR

Rick J. Griffiths (rjg42(AT)cam.ac.uk), Apr 20 2003


STATUS

approved



