Moschopulus wrote:Dr Brandon Zeidler's argument, if correct, would work for the nxn case. His argument would give a formula for the minimum number of clues.

He only gives a lower bound, never a claim about the actual limit. In the 2x2-case and 3x3-case, this coincides with the actual minimal number of clues (provided 17 is the minimum for 3x3), but there's no reason this should hold all the way up. This is often common, that when a bound B(N) is the actual limit for small values of N, the same formula gives bounds only, not the answer, for higher N.

If 85 is the minimal number of clues found, and Dr Zeidler's method gives 44 as a bound, there are several possible explainations to this:

- 44 is the minimum, but no example has been found yet

- The minimum is greater than 44.

- Zeidler's method only holds up to 3x3-grids

- Zeidler's method is wrong

Personally, I find the second statement to be the most reliable.

I'm only waiting for a simpler explaination of Zeidler's method, or an independent confirmation from someone who understands this matter. I'm originally a mathematician myself, but have almost no knowledge about communication theory. Actually, this thread alone has encouraged me to read and learn about it.