A255619 Number of length n+5 0..2 arrays with at most two downsteps in every 5 consecutive neighbor pairs

651, 1803, 5088, 14381, 40659, 114546, 322078, 907110, 2556858, 7205734, 20304363, 57202476, 161153983, 454067388, 1279391559, 3604760378, 10156531428, 28616171577, 80626959391, 227170254438, 640061685474, 1803397934760

Offset

1,1

Comments

Column 5 of A255622

Links

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

Formula

Empirical: a(n) = 3*a(n-1) -3*a(n-2) +8*a(n-3) -9*a(n-4) +30*a(n-5) -35*a(n-6) +12*a(n-7) -45*a(n-8) +56*a(n-9) -147*a(n-10) +177*a(n-11) -63*a(n-12) +18*a(n-13) +3*a(n-14)

Example

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

Crossrefs

Cf. A255622

Sequence in context: A110836 A252388 A043605 * A151736 A346138 A010087

Adjacent sequences: A255616 A255617 A255618 * A255620 A255621 A255622

Keyword

nonn

Author

R. H. Hardin, Feb 28 2015

Status

approved