A269071 Number of n X 4 binary arrays with some element plus some horizontally, diagonally or antidiagonally adjacent neighbor totalling two not more than once.

13, 76, 521, 3288, 20400, 123976, 742688, 4397376, 25791040, 150081504, 867569920, 4986765312, 28523566592, 162453499008, 921756644864, 5212543265792, 29388948548608, 165253519908352, 926962234179584, 5188178346090496

Offset

1,1

Links

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

Formula

Empirical: a(n) = 12*a(n-1) - 40*a(n-2) + 8*a(n-3) + 92*a(n-4) - 32*a(n-5) - 64*a(n-6) for n>7.

Empirical g.f.: x*(13 - 80*x + 129*x^2 - 28*x^3 - 20*x^4 - 48*x^5 + 4*x^6) / (1 - 6*x + 2*x^2 + 8*x^3)^2. - Colin Barker, Jan 18 2019

Example

Some solutions for n=4:
..1..1..0..0. .1..0..0..0. .0..0..1..0. .0..0..0..0. .0..0..0..1
..0..0..0..0. .0..0..1..0. .1..0..1..0. .0..0..1..0. .1..0..0..0
..1..0..0..0. .0..0..0..0. .0..0..0..0. .0..0..0..0. .0..1..0..0
..0..0..0..1. .0..0..1..1. .0..0..0..0. .0..0..0..0. .0..1..0..1

Crossrefs

Column 4 of A269075.

Sequence in context: A282643 A269085 A182077 * A283539 A060717 A044200

Adjacent sequences: A269068 A269069 A269070 * A269072 A269073 A269074

Keyword

nonn

Author

R. H. Hardin, Feb 19 2016

Status

approved