A068749 Number of potential flows in n X n array with integer velocities in -2..2, i.e., number of n X n arrays with adjacent elements differing by no more than 2, counting arrays differing by a constant only once.
1, 85, 87825, 1133641543, 184422574177355, 379827509377146575439, 9928923943603018785634645661
Offset: 1