Ugh. I see the problem is far more intractable than I had first
assumed. I suppose it'll be quite some time indeed before we see any
sort of complete optimality solution if the maximum number of moves
from solved is anything larger than the low twenties. I'll hunt
through the list archives for what's been accomplished on proving what
that number is... if anyone feels like giving me a brief refresher
instead, I'd appreciate it, though the whole list might not like to
see it all again.
Thanx again everyone.