A297226 Number of 4Xn 0..1 arrays with every 1 horizontally or antidiagonally adjacent to 1 neighboring 1s.

1, 19, 68, 207, 997, 4210, 16658, 68769, 284867, 1170146, 4807394, 19787328, 81424284, 334903296, 1377738399, 5668140481, 23317788357, 95926011656, 394630220291, 1623463820564, 6678736090662, 27475550500449, 113031264492453

Offset

1,2

Comments

Row 4 of A297224.

Links

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

Formula

Empirical: a(n) = 4*a(n-2) +29*a(n-3) +66*a(n-4) +121*a(n-5) +83*a(n-6) -a(n-7) -205*a(n-8) -224*a(n-9) +30*a(n-10) +473*a(n-11) -96*a(n-12) -289*a(n-13) -109*a(n-14) -3*a(n-15) +126*a(n-16) +160*a(n-17) -150*a(n-18) -112*a(n-19) +43*a(n-20) +124*a(n-21) -53*a(n-22) +3*a(n-23) -25*a(n-24) +6*a(n-25) -a(n-26) +a(n-27)

Example

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

Crossrefs

Cf. A297224.

Sequence in context: A228670 A044157 A044538 * A300463 A204675 A007546

Adjacent sequences: A297223 A297224 A297225 * A297227 A297228 A297229

Keyword

nonn

Author

R. H. Hardin, Dec 27 2017

Status

approved