A255105 Number of length n+6 0..2 arrays with at most one downstep in every 6 consecutive neighbor pairs.

540, 1008, 2032, 4338, 9297, 19263, 38010, 73278, 143045, 288057, 594045, 1228136, 2495244, 4970793, 9823140, 19533636, 39362880, 80112560, 163010352, 329127561, 659192991, 1316427636, 2637095196, 5313657069, 10747592751, 21727946097

Offset: 1

Author

R. H. Hardin, Feb 14 2015

Keywords

• nonn

Comments

Column 6 of A255107

Examples

			Some solutions for n=4
..0....1....0....1....1....0....2....0....1....2....1....1....0....1....0....0
..2....0....0....2....1....0....0....1....0....0....1....1....0....1....1....1
..0....0....2....0....2....0....1....1....0....0....2....0....0....1....2....1
..0....1....2....0....0....1....1....0....0....0....1....0....1....2....0....0
..1....1....2....0....0....1....2....0....0....0....1....1....1....1....0....0
..2....1....0....1....1....0....2....0....0....0....1....2....1....1....0....1
..2....1....0....2....1....0....2....0....1....0....1....2....2....1....0....1
..2....1....1....2....1....0....2....1....2....1....1....2....2....1....1....2
..2....1....1....0....1....1....0....1....2....0....1....0....1....2....2....2
..0....2....2....0....2....2....0....2....0....0....0....1....2....2....1....1
		

Links

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

Crossrefs

Cf. A255107

Formula

Empirical: a(n) = 3*a(n-1) -3*a(n-2) +a(n-3) +25*a(n-6) -42*a(n-7) +18*a(n-8) -10*a(n-12) +6*a(n-13)