A255106 Number of length n+7 0..2 arrays with at most one downstep in every 7 consecutive neighbor pairs.

927, 1616, 3042, 6141, 12662, 25578, 49611, 91887, 166290, 303969, 573853, 1118256, 2210103, 4340001, 8343339, 15695433, 29216435, 54612816, 103548108, 199304393, 386593848, 747736983, 1432037309, 2714684340, 5119381929, 9669662693

Offset: 1

Author

R. H. Hardin, Feb 14 2015

Keywords

• nonn

Comments

Column 7 of A255107

Examples

			Some solutions for n=4
..0....2....1....0....0....2....1....0....0....0....0....0....1....1....0....0
..1....2....1....0....2....2....1....1....0....1....1....1....0....2....0....0
..1....1....1....0....0....1....1....2....0....0....2....2....0....2....1....0
..1....2....0....1....0....1....1....0....0....0....2....0....1....2....1....0
..2....2....1....1....1....1....1....0....0....0....0....0....1....2....0....1
..2....2....1....1....1....1....2....0....1....1....0....0....1....2....0....1
..2....2....1....1....2....1....0....0....1....1....0....0....1....0....0....2
..1....2....2....1....2....1....1....0....1....2....0....0....1....2....0....2
..1....2....2....1....2....1....1....0....0....2....1....1....2....2....0....2
..1....2....2....1....2....2....1....0....2....1....2....2....0....2....1....2
..2....0....0....1....0....0....2....1....2....2....2....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) +33*a(n-7) -57*a(n-8) +25*a(n-9) -15*a(n-14) +10*a(n-15)