A183510 Number of n X 2 binary arrays with each element equal to either the sum mod 2 of its horizontal and vertical neighbors or the sum mod 2 of its diagonal and antidiagonal neighbors.

2, 4, 11, 24, 56, 121, 272, 612, 1373, 3082, 6914, 15501, 34784, 78034, 175061, 392748, 881084, 1976647, 4434500, 9948474, 22318763, 50070676, 112330190, 252005457, 565357670, 1268342734, 2845443827, 6383566410, 14321112518, 32128477051

Offset

1,1

Comments

Column 2 of A183517.

Links

R. H. Hardin, Table of n, a(n) for n = 1..200

Formula

Empirical: a(n) = 2*a(n-1) + a(n-2) - 2*a(n-4) + a(n-5) - a(n-6) - 6*a(n-7).

Empirical g.f.: x*(2 + x^2 - 2*x^3 + x^4 - 9*x^5 - 6*x^6) / ((1 + x)*(1 - 3*x + 2*x^2 - 2*x^3 + 4*x^4 - 5*x^5 + 6*x^6)). - Colin Barker, Mar 29 2018

Example

Some solutions for 3 X 2:
..0..1....0..0....1..1....1..1....0..1....0..0....1..0....0..1....1..0....0..0
..1..0....1..0....0..0....1..1....1..1....0..1....1..1....1..1....1..1....0..0
..0..0....0..1....1..1....1..1....0..1....1..0....1..0....1..0....0..1....0..0

Crossrefs

Cf. A183517.

Sequence in context: A034485 A362042 A018006 * A230984 A196195 A205500

Adjacent sequences: A183507 A183508 A183509 * A183511 A183512 A183513

Keyword

nonn

Author

R. H. Hardin, Jan 05 2011

Status

approved