Date: 30 January 1983 00:40 EST
From: Alan Bawden <ALAN @ MIT-MC>
Subject:  The shortest sequence of moves.
To: FONER @ MIT-MC
cc: CUBE-LOVERS @ MIT-MC, Tk.Foner @ MIT-OZ, HOEY @ CMU-CS-A
In-reply-to: The message of 29 Jan 1983  23:33-EST from Leonard N. Foner <TK.FONER at MIT-OZ>

The maximum number of moves (qtw) from solved is certainly not 17 or 19.
All we know about that number is that it is greater than or equal to 21.
It could be even larger.  There is a fair amount of sentiment that it is
probably around 28, but that's just intuition.