A note on busy beavers and other creatures

  title={A note on busy beavers and other creatures},
  author={Amir M. Ben-Amram and Bryant A. Julstrom and Uri Zwick},
  journal={Mathematical systems theory},
Consider Turing machines that read and write the symbols 1 and 0 on a one-dimensional tape that is infinite in both directions, and halt when started on a tape containing all O's. Rado'sbusy beaver function ones(n) is the maximum number of 1's such a machine, withn states, may leave on its tape when it halts. The function ones(n) is noncomputable; in fact, it grows faster than any computable function.Other functions with a similar nature can also be defined. The function time(n) is the maximum… 
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