Placid Platypus
The Placid Platypus function [1] is the minimal number of states of 2-symbol Turing machines that print exactly n ones when halt.
, because you can print each 1 in a state. Also if , then . On the other side, there is also a connection to a variation of the Lazy Beaver function (determined by ones rather than steps): if then .
Note that this function is not strictly increasing, and that it may be computable.
Values
| n | Example TM | |
|---|---|---|
| 1 | 1 | 1RZ--- (bbch)
|
| 2 | 2 | 1RB---_1RZ--- (bbch)
|
| 3 | 2 | 1RB1LA_1LA1RZ (bbch)
|
| 4 | 2 | 1RB1LB_1LA1RZ (bbch)
|
| 5 | 3 | 1RB1RZ_1LB0RC_1LC1LA (bbch)
|
| 6 | 3 | 1RB1RZ_0RC1RB_1LC1LA (bbch)
|
| 7 | 4 | 1RB1LC_0RC0RB_0LD0LA_1LA1RZ (bbch)
|
| 8 | 4 | 1RB1RZ_1LC0RD_1LA1LB_0LC1RD (bbch)
|
| 9 | 4 | 1RB1LD_1LC0RB_1RA1LA_1RZ0LC (bbch)
|
| 10 | 4 | 1RB1RZ_1LC1RA_0RC0LD_1RD0LB (bbch)
|
| 11 | 4 | 1RB1LD_0LC0RC_1LC1LA_1RZ0LA (bbch)
|
| 12 | 4 | 1RB0RD_1LC0LA_1RA1LB_1RZ0RC (bbch)
|
| 13 | 4 | 1RB1LB_1LA0LC_1RZ1LD_1RD0RA (bbch)
|
| 14 | 5 | 1RB0LB_0LC1RZ_1LE0RD_1RC0RA_1LD0LB (bbch)
|
| 15 | 5 | 1RB0LD_1LC0LB_1RD0RC_1LA0RE_1RA1RZ (bbch)
|
References
- ↑ James Harland. The Busy Beaver, the Placid Platypus and other Crazy Creatures. 2006.