On a 4 x 4 board what is the longest and the shortest 'tour' that a knight may make subject to no valid next destination being available, and not being able to revisit a prior square.
The knight starts in the top left cell (A).
A |
B |
C |
D |
E |
F |
G |
H |
I |
J |
K |
L |
M |
N |
O |
P |
|
Dismissing mirrored tours (A-P being the mirror) how many such routes are there?