A295116 Number of nX4 0..1 arrays with each 1 horizontally or vertically adjacent to 1 or 4 1s.

4, 20, 77, 326, 1373, 5793, 24347, 102398, 431050, 1813753, 7631302, 32111207, 135119039, 568549155, 2392325744, 10066404116, 42357266765, 178230161368, 749953993371, 3155644584471, 13278270334423, 55872091215736

Offset

1,1

Comments

Column 4 of A295120.

Links

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

Formula

Empirical: a(n) = a(n-1) +5*a(n-2) +22*a(n-3) +43*a(n-4) +52*a(n-5) +35*a(n-6) +35*a(n-7) +21*a(n-8) +14*a(n-9) +6*a(n-10) +9*a(n-11) -7*a(n-12) -a(n-14)

Example

Some solutions for n=7
..1..1..0..1. .0..0..0..0. .0..0..0..1. .0..1..1..0. .1..0..0..0
..0..0..0..1. .1..0..1..1. .0..0..0..1. .1..0..0..1. .1..0..0..1
..0..0..0..0. .1..0..0..0. .0..0..1..0. .1..0..0..1. .0..0..0..1
..0..0..0..0. .0..0..0..0. .0..1..1..1. .0..0..0..0. .1..1..0..0
..0..1..1..0. .1..0..0..0. .0..0..1..0. .1..1..0..0. .0..0..0..0
..0..0..0..0. .1..0..0..1. .0..0..0..1. .0..0..0..0. .0..0..0..0
..0..0..0..0. .0..0..0..1. .0..0..0..1. .0..0..1..1. .0..0..1..1

Crossrefs

Cf. A295120.

Sequence in context: A121257 A145563 A125669 * A303508 A258627 A082138

Adjacent sequences: A295113 A295114 A295115 * A295117 A295118 A295119

Keyword

nonn

Author

R. H. Hardin, Nov 15 2017

Status

approved