4 X 4 square grid graph coloring a rectangular array: number of n X 2 0..15 arrays where 0..15 label nodes of the square grid graph and every array movement to a horizontal or vertical neighbor moves along an edge of this graph.

A223396

4 X 4 square grid graph coloring a rectangular array: number of n X 2 0..15 arrays where 0..15 label nodes of the square grid graph and every array movement to a horizontal or vertical neighbor moves along an edge of this graph.