A295092 Number of nX3 0..1 arrays with each 1 horizontally or vertically adjacent to 1 or 3 1s.

3, 11, 33, 114, 377, 1249, 4151, 13765, 45704, 151720, 503627, 1671816, 5549529, 18421629, 61150537, 202988906, 673820905, 2236745220, 7424865048, 24646804474, 81814951110, 271584345815, 901522957697, 2992601212814, 9933925633736

Offset

1,1

Comments

Column 3 of A295097.

Links

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

Formula

Empirical: a(n) = 3*a(n-1) +3*a(n-3) -a(n-4) +11*a(n-5) -5*a(n-6) -14*a(n-8) -4*a(n-9) -9*a(n-10) -a(n-11) +a(n-12) +4*a(n-14) +a(n-16)

Example

Some solutions for n=5
..0..0..0. .0..0..0. .0..1..0. .1..0..0. .1..0..1. .0..0..1. .0..1..0
..1..0..1. .0..0..1. .0..1..0. .1..0..1. .1..0..1. .0..0..1. .1..1..1
..1..0..1. .0..0..1. .1..0..1. .0..1..1. .0..0..0. .0..0..0. .0..0..0
..0..1..0. .0..0..0. .1..0..1. .0..0..1. .1..0..0. .1..1..0. .0..0..1
..0..1..0. .1..1..0. .0..0..0. .1..1..0. .1..0..0. .0..0..0. .0..0..1

Crossrefs

Cf. A295097.

Sequence in context: A081250 A135247 A094539 * A032199 A018413 A004662

Adjacent sequences: A295089 A295090 A295091 * A295093 A295094 A295095

Keyword

nonn

Author

R. H. Hardin, Nov 14 2017

Status

approved