A258727 Number of length n+5 0..3 arrays with at most one downstep in every 5 consecutive neighbor pairs

1212, 2936, 7834, 21860, 59188, 149960, 370510, 941024, 2487276, 6650600, 17371025, 44270908, 112541478, 290771496, 762899717, 1998910152, 5175319416, 13289503784, 34202437664, 88756842476, 231356200114, 601422231744

Offset

1,1

Comments

Column 5 of A258730

Links

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

Formula

Empirical: a(n) = 4*a(n-1) -6*a(n-2) +4*a(n-3) -a(n-4) +52*a(n-5) -128*a(n-6) +108*a(n-7) -31*a(n-8) -68*a(n-10) +92*a(n-11) -31*a(n-12) +4*a(n-15) -a(n-16)

Example

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

Crossrefs

Cf. A258730

Sequence in context: A138480 A047627 A252213 * A234544 A047626 A204339

Adjacent sequences: A258724 A258725 A258726 * A258728 A258729 A258730

Keyword

nonn

Author

R. H. Hardin, Jun 08 2015

Status

approved