A198658 Number of nX4 0..7 arrays with values 0..7 introduced in row major order and each element equal to at least one horizontal or vertical neighbor.

2, 76, 3904, 344044, 40065880, 6046334324, 1099981072751, 231069206905205, 53332894057280732, 13062771135606107106, 3312119561085281340968, 856694689962959996618514, 224079649012945587508397744

Offset: 1

Author

R. H. Hardin Oct 28 2011

Keywords

• nonn

Comments

Column 4 of A198661

Examples

			Some solutions with all values 0 to 7 for n=4
..0..0..1..1....0..0..1..1....0..1..2..2....0..1..2..3....0..1..1..2
..2..2..3..4....2..2..3..4....0..1..3..3....0..1..2..3....0..3..3..2
..5..6..3..4....5..5..3..4....4..5..5..6....4..5..6..6....4..5..5..6
..5..6..7..7....6..6..7..7....4..7..7..6....4..5..7..7....4..7..7..6
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..17