A269014 Number of 4 X n binary arrays with some element plus some horizontally, diagonally or antidiagonally adjacent neighbor totalling two exactly once.

0, 48, 224, 2136, 10976, 73568, 390064, 2291728, 12190944, 67387784, 356115520, 1906181472, 9983123936, 52432319344, 272227610848, 1412208727736, 7276913394080, 37421599567712, 191604936958480, 978880041945808

Offset

1,2

Links

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

Formula

Empirical: a(n) = 4*a(n-1) + 28*a(n-2) - 78*a(n-3) - 264*a(n-4) + 296*a(n-5) + 527*a(n-6) - 252*a(n-7) - 324*a(n-8).

Empirical g.f.: 8*x^2*(6 + 4*x - 13*x^2 - 12*x^3) / (1 - 2*x - 16*x^2 + 7*x^3 + 18*x^4)^2. - Colin Barker, Jan 18 2019

Example

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

Crossrefs

Row 4 of A269011.

Sequence in context: A062248 A100146 A235542 * A265422 A211729 A211738

Adjacent sequences: A269011 A269012 A269013 * A269015 A269016 A269017

Keyword

nonn

Author

R. H. Hardin, Feb 17 2016

Status

approved