A302266 Number of 2Xn 0..1 arrays with every element equal to 0, 1, 2 or 3 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

2, 8, 29, 105, 384, 1405, 5135, 18766, 68589, 250693, 916272, 3348929, 12240187, 44737350, 163513041, 597632937, 2184322000, 7983600501, 29179707415, 106650542494, 389803024901, 1424712848861, 5207262571120, 19032314831801

Offset

1,1

Comments

Row 2 of A302265.

Links

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

Formula

Empirical: a(n) = 3*a(n-1) +a(n-2) +4*a(n-3) +4*a(n-4)

Example

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

Crossrefs

Cf. A302265.

Sequence in context: A208973 A365761 A100477 * A369268 A369299 A011367

Adjacent sequences: A302263 A302264 A302265 * A302267 A302268 A302269

Keyword

nonn

Author

R. H. Hardin, Apr 04 2018

Status

approved