A295711 Number of nX3 0..1 arrays with each 1 horizontally or vertically adjacent to 0, 1, 2 or 4 1s.

8, 57, 385, 2580, 17364, 116902, 786804, 5295555, 35642190, 239892457, 1614612772, 10867264744, 73142892532, 492293394940, 3313415396716, 22301175914018, 150099636663967, 1010256186136913, 6799600480817201, 45765190387685798

Offset

1,1

Comments

Column 3 of A295716.

Links

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

Formula

Empirical: a(n) = 5*a(n-1) +8*a(n-2) +22*a(n-3) +18*a(n-4) -2*a(n-5) -21*a(n-6) -20*a(n-7) -5*a(n-8) +3*a(n-9) +11*a(n-10) +a(n-11) -2*a(n-12)

Example

Some solutions for n=6
..0..0..1. .1..0..1. .0..1..0. .0..0..1. .1..1..1. .1..1..1. .1..0..0
..0..1..0. .1..0..1. .0..1..0. .1..1..0. .0..0..1. .0..0..1. .1..0..1
..1..1..0. .0..1..0. .0..0..0. .0..0..1. .1..1..0. .1..0..1. .1..0..0
..0..0..0. .1..0..1. .1..1..0. .0..0..1. .0..1..0. .0..0..0. .1..0..0
..1..0..1. .1..0..0. .1..0..1. .0..0..1. .1..1..1. .0..0..1. .1..0..0
..0..1..0. .1..0..1. .0..1..1. .1..0..0. .0..1..0. .0..0..0. .0..0..1

Crossrefs

Cf. A295716.

Sequence in context: A346228 A283125 A108666 * A164031 A297369 A023000

Adjacent sequences: A295708 A295709 A295710 * A295712 A295713 A295714

Keyword

nonn

Author

R. H. Hardin, Nov 26 2017

Status

approved