A268455 Number of length-n 0..6 arrays with no adjacent pair x,x+1 followed at any distance by x+1,x.

7, 49, 337, 2311, 15816, 108032, 736525, 5012171, 34047931, 230889543, 1563104184, 10564826628, 71293105297, 480355314513, 3231663192859, 21709801573961, 145636117720769, 975623832619371, 6526972402359763, 43608650962250889

Offset: 1

Author

R. H. Hardin, Feb 04 2016

Keywords

• nonn

Comments

Column 6 of A268457.

Examples

			Some solutions for n=6
..4....4....2....2....4....1....0....4....5....1....2....4....2....0....3....1
..4....3....6....4....1....0....0....2....4....0....4....3....3....4....6....1
..4....0....6....5....3....6....3....1....0....6....2....1....3....3....2....2
..0....4....4....6....0....5....5....0....4....6....3....3....4....2....4....0
..6....4....4....4....2....2....3....4....1....6....0....5....5....1....3....5
..3....5....1....4....2....0....5....3....0....5....6....1....1....2....1....2
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..210
• R. H. Hardin, Empirical recurrence of order 89

Crossrefs

Cf. A268457.

Formula

Empirical recurrence of order 89 (see link above)